As Becca Thacher on "Life Goes On" (ABC, 1989-93) Martin established a strong and sympathetic identity on the acclaimed series. Over the course of four years, she developed from awkward child to assured young woman coping with family issues, school pressures and a romance with an HIV-positive boy. Martin brought intelligence and a natural ability to her performance and earned both critical praise and an Emmy nomination.
She went on to head her own series, "Christy" (CBS, 1994-95), adapted from the Catherine Marshall novel, portraying a strong-willed and idealistic young woman who leaves her city home to teach at a mission school in the mountains of Eastern Tennessee in the early 1900s. While continuing to attend Yale, Martin returned to series TV as a interning counselor at a "Crisis Center" (NBC, 1997), a short-lived mid-season replacement set in San Francisco. In 1998, she interrupted her studies again in her senior year to undertake the regular role of medical student Lucy Knight on the hit NBC drama "ER". The actress eventually graduated from Yale in 2001.
Martin, a former Mouseketeer on the updated Disney Channel version of "The Mickey Mouse Club", shattered her good girl image with appearances in three TV movies: as an amoral teen plotting the murder of Tori Spelling in the fact-based "A Friend to Die For" (NBC, 1994); as an abused wife who murders her husband in "If Someone Had Known" (NBC, 1995); and as a confused young woman who recognizes herself as "The Face on the Milk Carton" (CBS, 1995). Martin continued to expand the range and depth of her work with "Hidden in Silence" (Lifetime, 1996), based on the true story of a teenage girl in Poland during World War II who hid 13 Jews in her attic.