Do you have any songs about Mother's? You could teach them songs and let them sing.
The girl across the hall from me always does Muffins for Mom - where the moms come in and eat breakfast. She takes pictures of each child with his/her mom and puts it into a fun foam frame and they decorate it together.
For dads she has Doughnuts for Dad...she hasn't done this one in several years, but they played games together at her last one.