FastHorse grew up in South Dakota,[5][6] where she began her career as a ballet dancer and choreographer but was forced into retirement after ten years of dancing[7] due to an injury.[8] Returning to an early interest in writing, she became involved in Native American drama, especially the Native American film community.[7][9] Later she began writing and directing her own plays, several of which are published through Samuel French (a Concord Theatricals Company) and Dramatic Publishing.[8][10] With playwright and performer Ty Defoe, FastHorse co-founded Indigenous Direction, a "consulting firm that helps organizations and individuals who want to create accurate work by, for, and with Indigenous peoples."[11] Indigenous Direction's clients include Macy's Thanksgiving Day Parade[12][13] and the Guthrie Theater.[14] FastHorse is a past vice chair of the Theatre Communications Group, a service organization for professional non-profit American theatre,[15] and current vice chair of the Board of Directors for Playwrights Horizons.