The two met Sunday for the first time at the 20th annual Bone Marrow Transplant celebration held at Loyola's Cardinal Bernardin Cancer Center.
McGavin is among 11 million donors registered with the National Marrow Donor Program, and she says she'd do it again.
"It's so simple. You get a little blood sample, and they put you on the registry. And then you go through a small surgery, but when you think about it in comparison to what Carolyn has been through, my small surgery is nothing," she said.