Not sure what my boyfriends children should call me?

Melanie

My boyfriend has two sons (4 and 6) who live in a different state with their mother. Once they are out of school, they will come spend the summer with us. Generally I would have no problem with them calling me by my first name, but their mother and I have the same name. Anyone have ideas for cute nicknames they could use? (My name is Melanie by the way lol)