- "People are the worst drug. They hook you and then they make you believe that they care and they leave or they fail you or they hurt you on purpose... There's a reason that God put a cage around your heart. People don't need other people. We need armor."
Maria describes Rosa:
- "She was electric. Impulsive. She was a hold-your-hair-back-when-you're-sick, slash-your-exes-tires type of friend. She was a total flake. Completely unreliable. But, somehow, when you needed her most, she always seemed to show up, right on time."
According to Liz, Rosa had a talent for art, poetry, and dancing. Rosa notably used to draw roses, which she drew on the gazebo when she first met Isobel, and on a mix tape that she left at the Wild Pony. Jim Valenti kept one of her rose drawings.
With her sister Liz, Rosa was born and raised in Roswell, New Mexico by her father Arturo Ortecho and her unnamed mother. Her mother taught her to play the guitar, but she later left, and Rosa and Liz were raised by their father. Rosa helped her father at the Crashdown Cafe working as a waitress.
Ten years before the start of the series, Rosa got into drugs and struggled with addiction. For a while she dated Frederico, who was also her drug dealer. By April 2008, Rosa appeared to be clean and was no longer seeing Frederico.
At some point, she learned the truth that her mother cheated on her father with Sheriff Jim Valenti and that he, not Arturo Ortecho, was Rosa's biological father. According to Noah, Rosa forced her mother to leave or she would reveal the secret. In 2008, Jim Valenti tried to help Rosa get clean.
By April 2008, she has become close with Isobel Evans, but Isobel was actually being controlled by Noah Bracken. Sometime in May, Rosa approached Isobel (who was herself) thinking they were friends, but Isobel blew her off. On prom night, Noah took control of Isobel's body again and went to see Rosa and apologize.
Rosa's friends Kate Long and Jasmine Frederick were upset with her for no longer supplying them with drugs, and they vandalized Rosa's car in retaliation.
In June 2008, Rosa apparently drove while intoxicated and got into a car accident, killing herself, Kate, and Jasmine. The three were actually killed by Noah. After seeing that Kate and Jasmine vandalized Rosa's car, Noah (while in Isobel's body) killed them by breaking their necks. When Rosa wasn't accepting of this, he killed her as well, saying she couldn't be trusted. Michael and Max, thinking this was done by Isobel, helped cover up the murder by placing the three girls in Rosa's car and making it look like an accident.
Rosa was intending to leave town, and she would have left the day after she died.
After her death, a handprint mark appeared over her face where Noah used powers to kill her. Her real autopsy was covered up with a fake by Project Shepherd to conceal that she was killed by an alien. After getting out of his pod, Noah somehow got Rosa's body and placed her in his pod, and keeping her preserved for ten years.
In 2018, Isobel and Michael find Noah's pod and Rosa's body inside it. They inform Max, who takes Rosa out of the pod and uses his powers to successfully resurrect her, but he expends so much energy that he dies. Rosa leaves the cave and outside finds Liz, who's searching for Max.
- There is a flower design at the bottom of her headstone from one of her drawings.
- There are inconsistencies on the exact date Rosa was born.
- January 17, 1989 - In the pilot episode, a pamphlet for Rosa's memorial gives this date. This pamphlet is shown again in episode 3.
- February 9, 1989 - In the second episode and the season one finale, her headstone instead shows this date. In the season finale, the pamphlet is changed to show this date as well.
- Between February 19 and March 20, 1989 - In episode 5, Maria says that Rosa is a Pisces.
- There are inconsistencies on the exact date Rosa died.
- June 1, 2008 - In the pilot episode, a pamphlet for Rosa's memorial gives this date. This pamphlet is shown again in episode 3.
- June 7, 2008 - In the second episode and the season one finale, her headstone instead shows this date. Frederico states this to be her date of death in episode 3. In the season one finale, the pamphlet is changed to show this date as well.
- June 8, 2008 - In episode 5, this is the night Rosa died according to a recording of calls made to the police that night.
- In the Roswell High book series, Rosa died of an overdose.