For 5-year-old Khyrstin Andrews, better known as Kyssi, and her mom, Marla, it was just as tough when Kyssi lost her hair the third time as it was the first.

In 2012, Kyssi was diagnosed with a Wilms' Tumor, a type of childhood cancer that affects the kidneys. After undergoing chemotherapy and radiation, she was declared cancer-free. But not long after that, her Wilms' Tumor returned and metastasized to her lungs. She underwent...