A noted child actor, Whelan first appeared on screen at the age of 11 and continued to take television roles until her matriculation into Middlebury College in 2004; Whelan graduated magna cum laude from Middlebury in 2008 after spending the 2006–2007 academic year as a visiting student at Lincoln College, Oxford.

[5] They developed a close relationship, and eventually Prysirr became her guardian, escorting her on trips to Los Angeles, where she soon found professional success.

The cast included Sela Ward and Billy Campbell as single parents trying to nurture a romance and eventually build a blended family together.

Once and Again was noted for the high quality of its actors,[6] particularly the younger cast members,[7] who were praised for their sensitive performances;[6] they were given screen time commensurate with that of the adult leads.

This lesbian storyline was dovetailed with an equally controversial plot involving Whelan's character in a doomed romance with her high school drama teacher "Mr. Dmitri", played by Eric Stoltz.

[9] After Once and Again wrapped up its three-year run, Whelan co-starred in the 2002 Lifetime Television movie, The Secret Life of Zoey, as a model student struggling with a prescription drug addiction.

[3] Whelan also narrates long-form nonfiction journalism, including articles from The New Yorker, The Atlantic, ProPublica, and Vanity Fair.