She was principal dancer with the New York City Ballet and performed with the company for 30 years, and toured in the U.S., Europe, and Asia.

In 1981, after auditioning before Suzanne Farrell, she received a scholarship to the summer intensive program at the School of American Ballet.

The following year, she re-auditioned for SAB's summer course, this time before Karin von Aroldingen, was accepted again, and chose to remain in New York afterward.

On the day she danced one of his works for the first time, as a corps member in Western Symphony at an SAB showcase, he died.

[4][5] Whelan joined the NYCB in 1984 as an apprentice and entered the company's corps de ballet in January 1986.

Whelan is also a frequent collaborator of Alexei Ratmansky, in works such as Russian Seasons and Concerto DSCH.

Whelan chose four choreographers—Kyle Abraham, Joshua Beamish, Brian Brooks, and Alejandro Cerrudo—to create dances for her.

[7] In 2015, she appeared in a mixed bill titled Whelan/Watson: Other Stories, alongside Royal Ballet principal Edward Watson in Linbury Studio Theatre, London.

[10] Whelan was appointed an Artistic Associate for developing new projects at New York City Center for a 2-year term from November 2014.

The two said they intended to work as partners, Stafford would be in charge of artistic operations while Whelan supervises programming.