Kelly was born in St. Paul, and moved to the Iron Range, Virginia, MN during middle school. She graduated from the College of St. Benedict in 1988 with a Bachelor of Arts degree in natural sciences and an Associate of Arts degree in music performance (flute). She earned her medical degree from the University of Minnesota in 1992, finished pediatric residency there in 1995, and began working at the Wayzata Children's Clinic shortly thereafter. She is board certified in pediatrics, and is a past president of Wayzata Children’s Clinic. She is currently the chief of staff at Children’s Minnesota and a director on the Children’s MN governance board. Her clinical interests include food allergies and asthma.

Kelly and her husband Bill live in Victoria. They have two young adult children, Will and Annie whom she credits for lots of practical parenting lessons that were never learned in medical school and residency. In her spare time she enjoys travel, music, biking, and reading.