She is the daughter of Margarita De Antuñano, Director of the Canada-Mexico Cultural Exchange Centre and a Spanish teacher and Barry McCarthy a retired Vice-principal.

[3] Then in 2006 she landed her first role as Elle Fanning's photo double in the film Babel starring Brad Pitt and Cate Blanchett.

At eight years-old, McCarthy had the opportunity to perform with Cate Blanchett and Gael García Bernal as daughter Cate—a role she shared with Elle Fanning—in the Golden Globe-winning film Babel.

In 2007, at the age of nine, McCarthy landed the role of Laura Westover for the TV movie Booky & the Secret Santa.

In 2009, at age 11, she was hired again to resume the role of Laura Westover in the movie Booky's Crush being the last film in the series.

McCarthy was part of the main cast of the film Zapped, she plays Taylor Dean, the antagonist of Zendaya's character.

[9] McCarthy plays the role of Abby Ackerman in the new YTV series Max & Shred, which also will be transmitted by Nickelodeon.