A Republican, Millner is a member of the Utah State Senate representing 5th District since 2023.

in Allied Health Education and Management from Southwest Texas State University, and an Ed.D.

She was Education Coordinator of the Medical Technology Program at Vanderbilt University, Instructional Developer in Medical Technology at Thomas Jefferson University, a lecturer at the School of Health Professions, Southwest Texas State University, and associate director of Continuing Education at the Edmonda Campus of Gwynedd Mercy College.

She began employment at Weber State College in 1982, and held such positions as Director of Outreach Education in the School of Allied Health Sciences, Assistant Vice President for Community Partnerships, Associate Dean of Continuing Education, and in 1993 she became vice president for University Relations.

[3] A Baptist, she is the only Republican in the Utah legislature who is not a member of the Church of Jesus Christ of Latter-day Saints.