Michelle provided the speaking and singing voice of Princess Odette in The Swan Princess and its sequels, The Swan Princess: Escape from Castle Mountain, and The Swan Princess III: The Mystery of the Enchanted Treasure, and the singing voice of Callisto for the Xena: Warrior Princess episode “The Bitter Suite“.
She appeared, briefly, as the college sweetheart of Billy Crystal in When Harry Met Sally. In 1996 she played Snow White in Coach episode “Grimmworld” as the girlfriend of Michael “Dauber” Daubinski (Bill Fagerbakke). Nicastro also had a minor role in Full House as Roxanna. She also played Lois “Old Lady” Scranton on an episode of Who’s the Boss?. From September 1989 to May 1990 she appeared as singer Sasha Schmidt on Santa Barbara during one of its Daytime-Emmy-award-winning years.
On the stage, she created the role of Ariadne in the 1983 Broadway musical Merlin. She was the first Éponine in the second United States tour of Les Misérables in 1988. Michelle recorded four albums released on the Varese Sarabande label.
Michelle died of breast and brain cancer on November 4, 2010, at home with her family. She was 50 years old.