Born to Filipino parents originally from Batangas and Pampanga, she grew up and currently lives in Los Angeles, California. She is the youngest of four siblings, Marian, Francisco and Cristina.
She is of Filipino, Chinese and Spanish descent. In an interview, she stated, "People ask me, 'Are you Spanish?' … "I say I have Spanish in me but I'm not just Spanish. I'm proud of my ethnicities and I will always be proud of being a Filipino".
Lalaine is also involved in many charity events, such as the AIDS benefit concert and *NSYNC's challenge for the children.
Lalaine was arrested in July 2007 and charged with felony possession of methamphetamine. She has pled guilty to the crystal meth charge, but her record will be expunged when she completes a drug-treatment program.
Lalaine has recently finished acting as the lead in the new movie Royal Kill, also starring Academy Award nominees Eric Roberts and Pat Morita.
Lalaine is normally credited by her first name only. She is commonly known for playing Miranda Sanchez on Disney Channel's Lizzie McGuire, alongside Hilary Duff. She reprised this role on the pilot of a spin-off series What's Stevie Thinking? about Miranda's younger sister, but this did not air in 2005 as originally expected and was scrapped. Lalaine's acting career began when she was cast in the Broadway production of Les Miserables in the roles of Young Cosette and Eponine.
When Lalaine returned to California, she acted in several television commercials, including some for Microsoft and Burger King. She also worked in the play Brundibar.
Lalaine's voice has been used for many movies, including Inspector Gadget and Lolita. She also played orphan "Kate" in the Wonderful World of Disney ABC-TV version of the movie Annie. She starred alongside AJ Trauth in the Disney Channel movie You Wish! as "Abby."
In 2004, Lalaine went to Philippines and made guest appearances on the GMA Network including the SOP Gigsters. She began hosting her own Filipino travel show Flipside, where she travels around the islands. She also promoted GMA Pinoy TV in San Francisco, California in 2005.