All you have to do is go to like Wal Mart or something and get a bottle of Shout Stain Remover and thta will take it right out. Just follow the directions on the bottle. My daughter is the same way but she likes to get things like grape juice on a brand new white shirt.
go to your local store (where ever you buy laundry detergent), and in that same isle, there are different stain removers. Find one you like, and try it. If it don't work very well, next time, try a different one.