a very specific type of song for groom and mother

The background: my mother passed away 11 years ago, my father is remarried to an amazing woman who will be my “mother of the bride.”
My fiancés parents both passed within this past year.
He would like to dance with my stepmom for the mother/son dance. I’ve listened to hours upon hours of music trying to find something that will work for them, and I’m coming up short. Please give me your suggestions!