Martin began her acting career at age 7, when her aunt who was a nanny for actor Michael Landon's children helped her land a guest spot on the Landon-produced series Father Murphy.

In 1989, Martin began the role of Rebecca "Becca" Thatcher on the family drama Life Goes On, which ran on ABC for four seasons.

Martin also co-hosted the 1989 pilot of America's Funniest Home Videos alongside Bob Saget.

In 1993, she played Sherry in Matinee, and made a guest appearance as Cleo Walker on an episode of seaQuest DSV titled "Brothers and Sisters".

In 1995, she starred in The Face on the Milk Carton, a TV film based on the book by Caroline Cooney about a teenager who finds out she was kidnapped from her real family 13 years prior and had been raised by the parents of her kidnapper.

When she left ER, she stopped acting for three years and returned to Yale to finish her degree in art history.

[6] In 2017, she played police officer Kimberly Leahy in seven episodes of the TBS comedy series The Guest Book.