Her writing credits include Freaks and Geeks, Buffy the Vampire Slayer, and Gilmore Girls.
[2][better source needed] In 2022, she asked an interviewer to call her Rebecca X, having "dropped her patriarchal last name.
In addition to her work in television, Kirshner writes children's stories and is a visual artist.
In 2016, her art show "How to Make Love to a Cactus" was exhibited in Los Angeles and Yucca Valley.
[5] She is the daughter of astrophysics professor Robert Kirshner, the great-granddaughter of Olympic hurdler William Rand and the descendant of Rebecca Nurse who was executed as a witch in Salem in 1692.