Cohn was discovered by actress Charlotte Rae when Rae and the producers of The Facts of Life visited Westlake School in Holmby Hills, California, while doing research for the show;[5] she had been asked by the principal to be a student tour guide for the group, who found themselves enchanted by her natural comic instincts as she led them around the campus.[6] Cohn was cast as Natalie Green and portrayed the character for the series' nine-year run (1979–1988), as well as in the reunion movie (2001).[7] In 2013, she commented on Charlotte Rae's lobbying on her behalf: "Mr. Reynolds calls me into his office. It seemed that Charlotte Rae had fallen madly in love with me, in part because I reminded her of her best childhood friend Natalie—and I was irrepressible, charming, and hilarious. So she asked the producers to create a part for me in the show. Honestly, the whole thing seemed so fantastic I didn’t know what to think."[8] After the show, she remained friends with Rae. Two months before her acting mentor's 90th birthday in 2016, when Cohn was unavailable to attend The Facts of Life reunion interview, she sent Rae a video message praising her decades-long friend for teaching her the craft of acting.[9] Cohn said that one of the reasons she did The Facts of Life Reunion in 2001 was that the actresses in the long-running 1980s series have been wrongly denied a cut of the syndication and DVD profits from the series. "We all never got paid and still don't get paid for DVDs and reruns... we felt we were owed."[10]
Cohn has continued her acting career outside of The Facts of Life. In 1984 she had a leading role as the daughter alongside Stockard Channing in RKO's video production of Table Settings. In 1986, she appeared in The Boy Who Could Fly as next-door neighbor Geneva. She also had guest appearances in other popular TV shows, including Charles in Charge (playing Buddy's sister Bunny, a young alcoholic, in the 1988 episode "Bottle Baby"), and two guest appearances in the second season of the cop drama 21 Jump Street (playing Rosa in the 1987 episode "Christmas In Saigon" and the 1988 episode "Chapel of Love"). In 2004 Cohn appeared in the WB comedy The Help. In 2010, Cohn played the role of Violet, the leading character in Casper Andreas's movie Violet Tendencies, and appeared on the Season 8 premiere of TLC's What Not to Wear on October 29, 2010. She appeared in an episode of Hot in Cleveland on July 13, 2011, on The Secret Life of the American Teenager on March 26, 2012, in Judson Theatre Company's Bell, Book and Candle in 2013,[11] and in The Middle on May 21, 2014. Cohn reprised her Velma Dinkley role in Lego Dimensions.[12]
