Makes me think of moon and I think it's lovely. Kids are going to make fun of a kids name if they want to. It's the way it is. If they don't like you, they'll find a way to butcher your name. As for your MIL, ignore her and don't talk to her anymore about names. As soon as she sees the sweet babe, she'll care less about your name choice. Good luck!
Re: MIL making fun of the name we picked out... *upset*
get used to it.