Although Fitzhugh provided the voice of the Bar Maid, her main work on The Great Mouse Detective was writing Ratigan's songs, "The World's Greatest Criminal Mind" and "Goodbye, So Soon" with Larry Grossman. Her previous writing credit was for the 1985 musical Grind, about an African-American burlesque house in 1930's Chicago. She received a Drama Desk Award nomination for Outstanding Lyrics and a Tony Award nomination for Best Original Score.

Fitzhugh briefly worked again with Mr. Grossman in 1989 for the American TV series, Shining Time Station, a children's program about Thomas the Tank Engine & Friends. It starred Ringo Starr as Mr. Conductor (from 1989 to 1991, afterward with George Carlin) and Didi Conn as Stacy Jones. Fitzhugh wrote the song, "Start Where You Are" for Season 1, Episode 01, "A Place Unlike Any Other." The sequence the song appears is separate from the main episode. A character named Tanya operates an old picture machine and it becomes a music video of children running around Keansburg Amusement Park in New Jersey.

Fitzhugh returned to theater in 2010 with the legendary Hal Prince in the stage production of Paradise Found. Based on the Joseph Roth novel Die Geschichte von der 1002. Nacht (The Tale of the 1002nd Night), the show opened on May 26, but then closed a month later. Work continued in 2012 when Fitzhugh collaborated with Michael John LaChiusa in Los Otros, a musical about a Southern California woman in love with Mexican-American man. It starred Julio Monge and Michele Pawk. 2014 was another busy year, working with Tony Award winner Michael John LaChiusa on the musical Nine Fathers for Ariel. The production is characterized as "a dance musical which centers on a mother's effort to provide her son with good fathering in the face of a war-obsessed world."