At the age of four, she was discovered at a fashion show by Broadway theatre producer Zev Buffman of drama school the Neighborhood Playhouse.

[2] In 1962, when she was five, Nickerson was in a play of Peter Pan as Wendy's daughter starring Betsy Palmer at Miami's Coconut Grove Playhouse.

[2] Her parents moved Carol and Nickerson back to New York City at 56th and Lexington in a studio apartment, while they stayed with her grandmother in Massachusetts.

[9][10][13] From 1972 to 1973, Nickerson joined the cast of The Electric Company as Allison, a member of the Short Circus music group.

[14] Also in 1974, Nickerson was Sophie Pennington, alongside Teddy Eccles, in the unsold television pilot If I Love You, Am I Trapped Forever?, based on M. E. Kerr's novel of the same name.

[3][12] In 1973, Nickerson starred in the TV movie The Man Who Could Talk to Kids, opposite Peter Boyle and Scott Jacoby.

[17] In 1975 she appeared in the satiric, beauty-pageant inspired motion picture Smile, as Miss San Diego Shirley Tolstoy, also starring a young Melanie Griffith and Annette O'Toole.

In 2003, Nickerson and some of her Willy Wonka & the Chocolate Factory castmates appeared on an episode of the British television documentary series, After They Were Famous, also directed by J.M.

In 2011, some of the Willy Wonka & the Chocolate Factory cast members, which included Nickerson, reunited for an episode of Top Chef: Just Desserts, which challenged the contestants to create an edible world of wonder.

[27] In September 2018, Julie Dawn Cole and Paris Themmen from Willy Wonka & the Chocolate Factory visited Nickerson after she was discharged from a rehabilitation center.