She graduated from Valley High School and St. Olaf College. She earned her elementary teaching degree, with an English as a Second Language (ESL) endorsement, from the University of Iowa and her International Diploma in early childhood Montessori teaching from the Montessori Centre International in London. Brennan and her husband, Scott, have two children: Lexi graduated from Valley High School in 2014, and Joe graduated from Valley High School in 2016.