Lilly began taking recreational classes at a local gymnastics gym in pre-school when she was four years old. From then on, she fell in love with the sport and would do handstands anywhere she went! She started competitive gymnastics at eight years old and quickly moved up the levels each year until reaching level 10 in 2021. Currently, Lilly trains 20 hours each week in the gym at Classic Gymnastics in Minnesota under coaches Bryon Hough, Charise Schrupp and Meghan Hargens.

Lilly is the daughter to Scott and Beth Timmerman and she has an older brother, Ben and a dog named Honey. Currently, she is an honor student at Mayo High School/Minnesota Online High School. She is a member of Mayo Honors Society, Mayo Key Club and Mayo Environmental Action Club. During Lilly's spare time, she enjoys playing piano, hanging out with her friends and being outdoors.

Lilly also spends her time volunteering where she plays piano at nursing homes and the Mayo Clinic. She rings the bell for the Salvation Army during the holiday season every year since 2020, organized a neighborhood canned food drive for ChannelOne, made blankets for Rochester's Women's Homeless Shelter, helped make gift bags for Nurse Appreciation Week at Mayo Clinic and made cards for teacher appreciation and essential workers appreciation during COVID. She also volunteered to help kids at a "fun run" at her local nature center and participated in an outdoor school trash clean up.