When James Garish married his kindergarten crush Liz Stipkovits on Feb. 17 near their hometown, McKeesport, Pa., it wasn’t with the expectations many couples entertain, about raising a family and growing old together.

Mr. Garish, 34, and Ms. Stipkovits, 34, had been dating since 2010, when he was serving in the Army in Iraq and looked her up on Facebook. They hadn’t been in touch since they were 5 and Mr. Garish was the kindergarten class rabble-rouser. But “I wanted to see how life had turned out for her,” he said.

It had turned out O.K. Ms. Stipkovits was then working as a medical receptionist and raising a daughter, Maleena, as a single parent in McKeesport. Four years later, though, she would get her first breast cancer diagnosis. By the time they decided to marry, in 2017, the cancer was advancing toward her brain.

“Little Bad Jimmy,” as Ms. Stipkovits remembered Mr. Garish from their school days, never left her side.