Alexa Vega. Alexa PenaVega (née Vega; August 27, 1988) is an American actress and singer. She is known for her role as Carmen Cortez in the Spy Kids film series and Shilo Wallace in the film Repo! The Genetic Opera (2008). In 2009, she starred as the title character Ruby Gallagher in the ABC Family series Ruby & The Rockits.