After her graduation from Colleyville Heritage High School, a year and a half later, she moved to Los Angeles to pursue acting.
When she was 17, she substituted for a friend at a meeting with a scouting agency and she met her manager, Randy James, who sent her some scripts.
She portrays a troubled, show off girl with superhuman powers who is trying to find her way in the world, with increasing cooperation and eventual romance with her male counterpart Kyle. In July 2010, it was reported that Alexander had been cast in the independent comedy-drama film, Loosies co-starring Peter Facinelli and directed by Michael Corrente.
Her role generated a large fan base hoping to see a spin-off show for her character. Alexander appeared in the 2013 film Savannah directed by Annette Haywood-Carter, about Ward Allen (Jim Caviezel), a real-life early 1900s aristocrat who starts an unexpected partnership with Christmas Moultrie (Chiwetel Ejiofor), a freed slave.
She appeared in the series Watch Over Me where she portrayed the controversial character of 'Caitlin Porter'.
In 2006, she had her first lead role in the horror film Rest Stop where she portrayed 'Nicole Carrow', a girl who escapes from home and goes on a trip with her boyfriend, which is unexpectedly interrupted at a rest stop by a deranged serial killer.
“Matt gets the vision of my videos and my book,” Tyler tells Just
She reprised the role twice in special crossover guest appearances on the TV series Agents of S. In the series Alexander portrayed Han Solo in battle against Indiana Jones for the title of best Harrison Ford character.In 2007, she had her second lead role, also in a horror film.In Hallowed Ground she played 'Elizabeth Chambers', a girl stranded in a small town inhabited by a sect that plans to use her as a vessel for the rebirth of their founder.She also has had guest roles on the show CSI: Miami where she played 'Jenna York', a flight attendant involved in a murder case; and in Bones where she played 'Molly Briggs', a student connected to the victim of the episode. Alexander has done a photo shoot with her co-star Matt Dallas from Kyle XY for the photographer Tyler Shields.In September 2009, it was reported that Alexander would portray Sif in the live-action superhero film, Thor, directed by Kenneth Branagh and released in May 2011. She also appeared in a Matthew Perryman Jones music video of the song "Save You" released in September 2009.