The Healing Garden by Heather B. Moore

Spring 1981
Eighty-three year old Sam Davis has always wondered what happened to his high-school sweetheart. But instead of finding the means to track her down, he’s stuck in an assisted living center, reliant on others around him. His grandson, Wyatt, questions Sam’s memories, and it seems that he’ll never find the answers he’s been searching for.
Anita Gifford, single mom in her mid-30s, is reluctant to spend community service hours at the assisted living center in their town. But her fourteen-year-old daughter Carly has to work off her school suspension. So instead of a relaxing weekend after a long week of work, Anita takes Carly to the center where they meet Mr. Davis. An unexpected bond forms between the teenager and elderly man, one that might bring healing to the both families, past and present.