"Lucas, you're hot."
- ―Sam to Lucas
Samantha “Sam” Stewart is Tiffany and Ralph Stewart’s sister, the sister-in law of Jalen Long and Gwen and Hayden Stewart’s youngest daughter. She is also Lucina Stewart’s aunt and Bryce Summers’s aunt-in-law and the great aunt of Lucien Summers and the great aunt-in-law of Luna Snow. Sam is the widow whose husband Ethan died in a car accident leaving her to care for her son Kellan Stewart. Sam is known to have a massive crush on Lucas Stone.
She is portrayed by Ariel Winter.
Biography
Early life

Sam crushing on Lucas.
Sam Stewart was born in Lacey, Washington in 1999, to Gwen and Hayden Stewart. She is the younger sister to Tiffany Stewart. She once had a younger brother Ralph Stewart but he died after birth due to breathing problems. Sam was only young when Tiffany met Jalen Long who lives in a foster home after the lost of his parents. Tiffany and Jalen get along well and Jalen always comes over to Tiffany's house to play where he is welcomed by Tiffany's family. One morning, Gwen and Hayden tells Tiffany that they decided on adopting Jalen much to Tiffany's delight however, they heard the news that Jalen ran away from his foster home due to the police thinking he raped his foster sister Elena Margaret and beat their foster dad for silence which was later proved to be false.
In mid-winter of 2005, a family move next door to Tiffany and Sam where she gets to meet Lucas Stone whose father Kendall Stone is the chief of police and the two of them became best friends. Sam meets Lucas where she developed a huge crush on Lucas and he was never aware of it until he was ten. He never had any feelings the same way Sam does but does think of her as a sister to him.
Forever Together

Sam’s crush on Lucas continues as she grows up. As Lucas enters Timberline High School, he begins dating Meghan Valentine which devastates Sam but is happy for Lucas though she wishes to be the one dating him.
Soon Sam attends Timberline as a freshman as Tiffany, Lucas, Meghan and their friends became seniors. On Lucas and Meghan's second anniversary, Meghan was killed in a car accident by Lucas's tormentor Justin Knox causing Lucas to be devastated. After Lucas got over his depression, Sam asks Lucas out to go to Sadies with him which he accepts. Although Sam sees that Lucas doesn’t feel the same way as her, she does accept being friends with him. After the dance, Sam encourages Lucas to go out with Tina Haase, who developed a crush on him, as Lucas encourages her to accept Rex Carter’s offer to go out with him. As thanks for helping Lucas moving on, he gives Sam a kiss on the cheek. Sam then goes out with Rex becoming his girlfriend. However, she finds out that Rex has been cheating on her with numerous girls in school after seeing Lucas and his friends trying to catch him in the act and ends her relationship with Rex. She then thanks Lucas for it by having her first kiss with Lucas.
On May 16, 2015, while Tiffany and Lucas went with their friends to Bri Evan’s White-Out party, Sam was outside on Tiffany’s balcony when Lucas’s house was on fire with Lucas’s family in it. During that, she thought she saw someone come out (caused by Aro, Marcus and Caius of the Volturi) and ran but it was too fast for Sam to catch it. Lucas’s family was rescued but they died from the fire allowing Lucas to live with their neighbor Beth Belisle who became Lucas’s guardian until he graduates.
Lucas graduates high school and announces that instead of going to college, he is traveling to find some meaning in his life and will leave Lacey.
A New Life
Sam never appeared in the story but it is revealed in Forever Together that Lucas left the Cullens in Forks and returned to Lacey to see his friends before they go off to college. Sam sees Lucas and his new appearance, due to Lucas being turned into a vampire, and fainted. She wakes up in Lucas’s arms and whispering compliments of Lucas’s new look although Lucas can hear it.
Happily Ever After

Sam at Lucas and Krystal's wedding.
Sam and Tiffany received an invitation to Lucas’s wedding where he is getting married to Krystal Diamond. They attend the wedding where Sam is talking to the Cullen women. Sam watches Lucas gets married to Krystal and was seen at the reception congratulating to the couple where Sam’s crush on Lucas is still showing.
Full Of Surprises

Sam's shock face meeting Lucina.
Sam appeared in the story where she and her parents came to the Cullen house to find Tiffany there, (who by now had become a vampire) after not hearing from her in a while and traced her here. Sam then tells Tiffany that she’s engaged to Ethan who she has been dating and is going to college in Arizona with him. Because of it and with their parents traveling, Tiffany allows them to meet her daughter Lucina Stewart unaware to them that Lucina is half-human and half-vampire and will grow rapidly so Sam and her parents have no clue about the supernatural. During the trip, Sam’s crush to Lucas is still shown.
Value In Belief
Sam was mentioned in the end of the story by Tiffany explaining that she and Ethan got married and are living together in Arizona when Tiffany was describing her heartache.
Have A Purpose
Sam had to stay with Ethan to take care of him since he’s sick and was unable to come to Tiffany’s wedding with Jalen who she reunited with and became her mate. Luckily, Alice Cullen FaceTime the wedding for Sam to see. On Lucina’s birthday, Sam sends her a collection of hair bows.
A Christmas Surprise
"Wait a minute, so that means that this whole time Lucas is… OH MY GOSH!"
- ―Sam on Lucas
Sam and her parents came to the Cullens on Christmas Eve to spend the holidays with Tiffany by a surprise visit. They were completely shocked to see that Lucina is all fully grown up despite that she’s only six.
As the new Volturi, the Cullens told Sam and her parents and the guests of their story and the events that have happened revealing about the supernatural and what Tiffany, Lucina, Lucas and the Cullens truly are. They made one adjustment to the law about revealing their existence; if a civilized vampire has any living family member or someone connected to, they have the right to know as long as they don't reveal the existence to other humans.
In the epilogue of the story, Sam is pregnant and is living with her parents back in Washington after Ethan died in an accident leaving Sam a widow. Sam states that she will not be with any men after knowing about supernatural as she wants to focus on raising her child. She has also changed back to her original surname.
Long Live Life
Sometime later, Sam gives birth to her son Kellan Stewart. Sam made a cameo appearance on Lucina’s marriage to Bryce Summers. She also appeared years later to her great nephew Lucien Summers’s marriage to Luna Snow.
Physical appearance

Sam Stewart.
Sam has long brown hair in soft waves, which is passed down to Lucina, and light brown eyes standing at five feet and four inches. She also has a healthy curvy body.
Personality and traits
Sam is known to have a massive crush on Lucas. Whenever she’s with him, Sam always blushes and acts shy towards him mostly by stuttering. Apart from it, Sam is very friendly and loving to other people and has a big heart for her family as she cares deeply to the people close to her.
Relationships
Sam Stewart is the widow of Ethan and the mother of Kellan Stewart. She is the daughter of Gwen and Hayden Stewart and the middle sister of Tiffany and Ralph Stewart as well as the sister-in-law of Jalen Long. She is also the aunt of Lucina Stewart and the aunt-in-law of Bryce Summers along with being the great aunt of Lucien Summers and the great aunt-in-law of Luna Snow.
Lucas Stone

Sam's crush: Lucas Stone.
"You are a beautiful girl who deserves to be with an amazing guy who will love you and always will."
- ―Lucas to Sam
Lucas Stone is Tiffany’s best friend who Sam has a crush on.
When Lucas moved next door to her and Tiffany in Lacey, Sam developed a huge crush on Lucas since she was five and she still does throughout the series. Lucas knows about Sam having a crush on him but only sees her as a friend but the two of them care about each other as seen when Lucas found out the truth about Rex cheating on Sam.
Sam's crush on Lucas continues out through the series hoping that Lucas's feelings for her would change. Sam asked Lucas out to Sadies to help Lucas be ready to move on after the lost of Meghan and encourages him to ask Tina Haase out. When Sam found out that Rex was cheating on her, she thanks Lucas for telling her and got her first kiss with him. Lucas returned to Lacey to see his friends and Sam got to see Lucas as a vampire causing her to faint. In Happily Ever After, Sam was invited to Lucas's wedding and came there to congratulate him even though she still has feelings for him. They saw each other again in Full Of Surprises where Sam's feelings are still shown to Lucas even though she's engaged to Ethan much to Krystal's annoyance. In A Christmas Surprise, Sam visits the Cullens for the holidays where she is told of the truth of them being vampires bringing her and Lucas closer. Her feelings are still shown there.
Tiffany Stewart

Sam's sister: Tiffany Stewart.
"Get your heart checked Sam."
- ―Tiffany on Sam
Tiffany Stewart is Sam’s older sister.
When Lucas moved into their neighborhood, Sam developed a huge crush on Lucas and has been like that for ages. Tiffany teases about it, mostly to embarrass Sam in front of Lucas for fun which ends up being chased by her sister. None of the less, the two care about each other as sisters as Sam always looks up to her sister, admiring her.
When Tiffany was introduced into the supernatural, she was worried about how to hide Lucina from Sam and her parents but hearing that Sam will be living in Arizona, the Cullens believe it's safe for Lucina to meet Sam since she will visit less with her marriage with Ethan.
In A Christmas Surprise, Sam surprises Tiffany to spend the holidays with her and the Cullens where Sam has been told of the supernatural and Lucina's true nature since the law has made a change thus bringing the two closer. Tiffany named her daughter after Sam as her maiden name.
Lucina Stewart

Sam's niece: Lucina Stewart.
- "I love you Aunt Sam."
- "I love you too Lucina."
- ―Lucina to Sam
Lucina Stewart is Sam’s niece who is half-human and half-vampire.
After Lucina's birth, the Cullens were unsure on how to conceal Lucina from Tiffany's family since they must not know about the supernatural until they hear that Sam is engaged to Ethan and will be living in Arizona while she attends college there which means that Sam won't be able to see her niece that often so it was safe for Lucina to meet her. The two meet and gotten close instantly. Sam is cheered by the fact that Lucina's middle name is after Sam's birth name, Samantha. Lucina is shown to have her hair in soft waves inherited from Sam. Sam left after meeting Lucina and they haven't seen each other since. Sam would send Lucina collection of hair bows as a birthday present which Lucina loves.
In A Christmas Surprise, Sam makes a visit to spend Christmas with Tiffany and Lucina and the Cullens. When she saw Lucina, Sam was shocked at her appearance in a teenager's body at a young age. Sam soon was told about the supernatural and about Lucina's true nature since the law has made a change thus bringing the two closer even though it was a lot to take in. Lucina even allowed Sam to communicate with her mentally.