Raquel Rohlfing was desperate. Her 4-year-old son, Mikalo, had just relapsed with leukemia. He would need a bone marrow transplant. Three years of dealing with cancer had long since depleted her savings; in fact, the single mother and her son had been living in homeless shelters, Mikalo often trailing an IV pole.

“I told the hospital I had nowhere to go,” says Rohlfing, 36, a cheery woman who wears a necklace with the words, “Live Strong Mikalo.”