All of the following are in the DT:

When you and I were young, Maggie

Lovely Agnes

You are my sunshine

Tell me why (the stars do shine) (this one's great in 2-part harmony)

If your mother was born in 1916, check out sites online that list popular songs for specific years. I "googled" "popular songs from 1916" and got over 14 million hits!

Good luck, and happy birthday to mom! My mom (The Survivor) is going to be 80 in May, and you've given me some inspiration- thanks!