[1] She is the daughter of Earle A. Tarr, Jr. (a waterworks manager and salesman of real estate), and Regina (a teacher).
[6] The romantic fantasies that she writes under the name Caitlin Brennan[8] feature "dancing horses" modeled on those that she raises.
The trilogy focuses on a race of Elves with supernatural powers, secretly living in medieval society.
[11] Tarr consulted the history books The Crusades Through Arab Eyes by Amin Maalouf and The Assassins: A Radical Sect in Islam by Bernard Lewis, as part of her research for Alamut.
The Epona series dramatizes the ideas of archaeologist Marija Gimbutas about a matriarchal society existing in Paleolithic Europe.