Caragh M. has been writing since she graduated from Johns Hopkins University with a master's degree in writing seminars. O'Brien has worked as a high school teacher, a romance novelist, and now a teen novelist. YALSA named her novels Birthmarked and Prized Best Literature for Young Adults. Birthmarked was also chosen for the ALA 2011 Amelia Bloomer List and was a Junior Library Guild Pick. She writes from her home in Connecticut, where she lives with her family.