Rosa, the youngest of the five Santos children, has had her fill of heartbreak in her young life. By her teenage years, she had lost her father and sister, Maria. Another of her sisters, Julia, was forced into hiding after a hired gun attempted to kill her.

Rosa was one of the lesser active members of the Santos clan, primarily because of her young age. In June 2001, Rosa once again returned to the canvas. Now a high school student, Rosa was beginning to test the boundaries set in place by her mother, Isabella. Isabella, however, remained protective of her youngest child, stating that it wasn't easy for her to raise Rosa as a single parent. Rosa tired of Catholic school and wanted to be amongst her peers - in public school. With the help of her brother, Mateo, Rosa was able to convince her mother into letting her attend her senior year of school at Pine Valley High.

Rosa became the target of teen male machismo when school jock Marcus Dunn set out to take Rosa's virginity. Marcus, a drug abuser and hot head, was watched closely by Gabriel Devane. However, nearly everyone felt that the socially awkward Gabriel was the troublemaker. Marcus' scheme became evident over time and Rosa was safely extricated from what could have been a violent and dangerous situation.

Rosa become embroiled in the Proteus drug plotline when someone slipped a large bag or marijuana into her purse during Lorenzo's baptism. Mateo arranged for Rosa to leave Pine Valley during the winter of 2002 in order to keep her safe.