Lea White is a survivor in every sense of the word. The U.S. Marines veteran left home at age 16 and developed a stubborn determination to overcome adversity along the way.

She’d just gotten a divorce, moved to California, suffered the loss of two pets and was drowning in work when life dealt her another blow: an acute myelogenous leukemia (AML) diagnosis in April 2004.

“I’ve always been a survivor, and so this was just...