What mother wouldn't love a portrait of themselves as drawn by their child?! Inchmark has the simple steps to create the portrait and also has a free printable for questions that a child can answer about their mom as well.
Here's a sweet Mother's Day card idea that uses fingerprints for lily of the valley. You'll be surprised how the leaves are made though! Visit Léon, Pas Sur Les Murs for the tutorial. English translation here.