Derr was raised as Jill Carol Mulvay in Salt Lake City.
Longtime residents of Alpine, Utah, they have also lived in Fontainebleau, France,[1] and Tolochenaz, Switzerland.
She also co-wrote Women of Covenant: The Story of Relief Society (Salt Lake City: Deseret Book, 1992; 2000).
Her articles have appeared in BYU Studies, Journal of Mormon History, Utah Historical Quarterly, and Dialogue: A Journal of Mormon Thought Her paper on Sarah M. Kimball received first prize in the 1976 Utah Bicentennial Biographies contest.
In 2016, the Church Historian's Press released the book The First Fifty Years of Relief Society: Key Documents in Latter-day Saint Women's History, which was edited by Derr, Matthew Grow, Carol Cornwall Madsen and Kate Holbrook.