First I cut a piece of foam to make a heart. I taped it to the bottom of a cup to make like a stamp.
Then I covered it with fabric paint. I used purple since it's her favorite color and I already have tons of purple shirts to match them with.
Then I stamped them on the knees of both legs. I used a paint brush to fill in any big gaps. Then I layed them to dry overnight.
Cute, cute and easy.