Ubach was born in Downey, California, the daughter of Sidna and Rodolfo Ubach. Her father was from San Juan, Puerto Rico and her mother, raised in Los Angeles, was from Sinaloa, Mexico.
In 1994, she received a positive review from The New York Times for her role as a Jewish girl in Kindertransport at the Manhattan Theatre Club. During this stage, she also landed a regular spot as Josie the assistant in the TV series, Beakman's World. Her early film roles include Airborne (1993), Sister Act 2: