When my husband, Jeff, was diagnosed with bile duct cancer in June 2019, I’d already been donating blood for almost 20 years. I especially enjoyed donating platelets, both because I could do it more often, and because it was a little harder to accomplish. Afterward, I’d usually be pretty wiped out, but it felt good, knowing I was really helping people.

Before Jeff and I were married, his mother thanked me for being a longtime blood...