Subsequent Broadway roles include Cosette in Les Misérables (1987), Florence Vassy in Chess (1988), and Amalia Balash in She Loves Me (1993).

Kuhn (pronounced Coohn, Cohn) was born in New York City to Jewish parents and grew up in Bethesda, Maryland.

[9] Kuhn appeared in the Trevor Nunn-directed Chess, with music by Benny Andersson and Björn Ulvaeus and lyrics by Tim Rice in the 1988 Broadway transfer from the West End, playing one of the main roles (Florence Vassy).

She reprised her role of Florence Vassy later in January 1989 in a Carnegie Hall concert performance with the rest of the Broadway cast, which was a benefit for the Emergency Shelter Inc.[13] She also performed in a Chess concert version in 1989 in Skellefteå, Sweden, during a chess World Cup final tournament, where she joined with Tommy Körberg and Murray Head, two principal actors from 1986 West End production of the musical.

[15] Kuhn's next major Broadway project, Two Shakespearean Actors (1992), despite a cast that included Brian Bedford, Frances Conroy, Hope Davis, Victor Garber, Laura Innes and Eric Stoltz,[16] was commercially unsuccessful, closing after 29 regular performances.

In December 1993, Kuhn played the role of Betty Schaefer in the U.S premiere production of Sunset Boulevard at the Shubert Theatre in Los Angeles.

[22] Kuhn appeared in the Broadway concert King David which was a 1997 Disney project with a book and lyrics by Tim Rice and music by Alan Menken and directed by Mike Ockrent.

[23] Kuhn sang in the second annual benefit concert for The Actors' Fund of Funny Girl in September 2002 at the New Amsterdam Theatre, with different actresses taking on the role of Fanny Brice.

and "People" of which Andrew Gans of Playbill wrote: she "provided an intense, moving, full-voiced 'People,' sensationally belting 'are the luckiest peeeeeeople (wow!)

[30] On October 23, 2007, Kuhn returned to the Broadway production of Les Misérables after 20 years, this time assuming the role of Fantine.

[31] Kuhn portrayed Fosca in the Off-Broadway Classic Stage Company revival of the Stephen Sondheim-James Lapine musical Passion from its opening in February 2013 through its scheduled closing in April 2013.

[33] In 2013, Kuhn originated the role of Helen Bechdel in the off-Broadway Public Theater production of the musical Fun Home, which began its run September 30, 2013 and opened officially on October 22, 2013.

[37] She played Golde in the Menier Chocolate Factory (London) production of Fiddler on the Roof which began on November 23, 2018, and ran to March 9, 2019.

[48] Kuhn briefly appeared in the film Long Time Since (1998) and supplied the vocals for the movie's soundtrack,[49] which includes a rendition of Auld Lang Syne.

[56] Kuhn also teaches a song interpretation class at Michael Howard Studios in New York City, where she studied earlier in her career.