The recipient of a bachelor's degree in mathematics from Penn State University, Hilary Agnello subsequently earned a master's degree in curriculum and instruction from National Louis University and began teaching basic and advanced algebra to students at Geneva High School in 2006. The following year, Hilary Agnello joined Crystal Lake Lundahl Middle School, where she taught core mathematics principles to seventh grade students in basic and advanced programs. She taught at the school for four years, during which time she earned a Home State Bank Teacher of the Month nomination.

In 2014, Hilary Agnello began teaching math courses at McHenry County College, while also tutoring students through the Sage Learning Center. Beyond teaching students, she has leadership experience as an instructional coach with Round Lake Middle School, where she spent two years instructing a team of 16 math teachers through a complex professional development program. Building upon that experience, Ms. Agnello is working toward a doctor of education in higher education leadership from National Louis University, where she has been nominated for membership in the National Society for Leadership and Success. In her spare time she enjoys reading, working out, and playing volleyball.