Thousands of runners in tutus and tiaras crossed the finish line this past weekend during the Disney Princess Half Marathon Weekend presented by Children’s Miracle Network Hospitals and amongst them was Katie Karp of Winter Garden, Fla., living out her own real life fairytale.

As a little girl, Karp was an active runner and lacrosse player who always had a fascination with running. At the young age of 12-years-old, she began experiencing pain in her left leg the night before her first track meet. After the event, the pain became so tremendous that her parents decided to take her in for an MRI the following day, which marked the start of Karp’s journey with osteosarcoma, or bone cancer.

Just a week after being diagnosed, Karp began the fight of her life and was determined to not let cancer win. She spent over 100 days and nights in the hospital as she went through chemotherapy treatments and eventually underwent the surgery that ultimately saved her life.

The rare surgery resulted in 12 inches of her thigh bone being removed and replaced with an internal prosthetic. Karp is one of the few people in the world to have had this radical limb salvage procedure. The goal going in to the surgery was to just survive and walk again, but ultimately Karp wanted to get back to what she has always loved – running.

Fast-forward to today and Karp is celebrating six years cancer-free and crossed over the finish line of her first half marathon with her two oncologists and physical trainer. Karp is a true inspiration and to this day, uses her experiences with cancer to help children currently fighting for their own “Happily Ever After” ending.

Check out the video to see Karp’s journey during the Disney Princess Half Marathon Weekend!

If you are running in an upcoming runDisney race and have an inspirational or extraordinary story like Karp, we’d love to hear it! Please submit your story for consideration by emailing WDPR.DisneySportsStories@Disney.com.