Rose is born from a union between Talia Briar and Will Scarlet. However, Talia is not ready to become a mother yet, and instead entrusts Rose to her mother Chrysalis to raise and look after. Talia keeps her pregnancy a secret from Will, as she does not want him to think Rose's existence meant their relationship was more important it actually was. Rose is raised by Chrysalis until childhood, when Carabosse kills Chrysalis and assumes her form. She continues to be raised and looked after by Carabosse, unbeknownst to Rose. When Rose turns sixteen, she is abducted by her father Will Scarlet, who reveals to her who he is. Rose, shocked to see her father, lives with him and the Merry Men until Carabosse arrives with Rose's mother Talia. Talia takes Rose back to her house, only for Carabosse and Rose's aunt Poppy to kidnap her and take her back to Carabosse's lair, where Poppy uses the Potent Sleep elixir on Rose to curse her into a deep sleep. Rose wakes up when Carabosse is defeated by Glinda.
After the ordeal with Carabosse, Rose is eager to learn how to defend herself. Rose befriends neighbor Baba Yaga and discovers that she is a witch. Baba encourages Rose to become a witch herself, and learn magic. Rose confronts Poppy and asks her to create a Bottled Witches' Brew, an elixir that can turn people into witches, and claims that Poppy owes her for working with Carabosse. Poppy obliges, and Rose eventually becomes a witch. However, the power begins to go to her head, and Rose becomes increasingly arrogant. After a while, Rose becomes irritated by Dorian and tries to kill him. When Glinda finds out, she and Rose duel, and Glinda defeats Rose before fleeing with Dorian. Over time, Rose and Baba become closer, until one night they hook up. Rose laments about her defeat against Glinda, and Baba Yaga agrees to temporarily transfer some of her powers to Rose. Rose, now backed by Baba Yaga's magic, locates Glinda and challenges her to another duel which she wins. Rose then exiles Glinda and transforms Dorian into her Frog Footman. High on power, Rose visits Baba Yaga and states that Baba's magic belongs with someone who will test the boundaries of magic rather than someone who uses it for blind malice. Rose then magically incinerates Baba, absorbing the rest of her magic and becoming incredibly powerful.
- Rose alludes to the princess from Sleeping Beauty.
- She also alludes to Red Riding Hood from Little Red Riding Hood.
- The name "Rose Scarlet" refers to "Rose Red" from the fairytale Snow White and Rose Red.
- The name "Rose Briar" is based on "Briar Rose", which is the princess's alias in Sleeping Beauty.
- Like Sleeping Beauty, Rose is protected by a good fairy, while a wicked fairy poses a threat and eventually curses her into a deep sleep.