When 9-year-old Kaylee Tolleson started having stomach pains last year, doctors initially thought it was constipation. But an ultrasound later revealed a softball-sized tumor in her abdomen and she was diagnosed with stage 3 ovarian cancer. After missing part of her third-grade school year to undergo surgery and chemotherapy, Kaylee is now cancer-free! See how this brave girl who touched hearts across the country is now on a mission to help others battling the disease.