To all who know her, Sienna Page is “your typical sweet little 3-year-old, full of vibrance and energy," said her father, Chris Page of Ridgefield. She always has an upbeat, positive outlook, he said.

Once at Children’s Health in Dallas, Clayton underwent a CT scan, which found a “tumor ... which was larger than a grapefruit. The Wilms tumor appeared “really fragile,” much like a ...