Milk snakes..........?

I really, really, really want a snake. My mom is totally against the idea of one but FINALLY decided to let me have one...IF......it's little and doesn't eat mice. So the only one i've found so far that seems to be a good pet is the Garter Snake...But I really LOVEEEE the Milk Snakes. I was wondering can they be taught a different diet then pinkies or live mice?? They are soo beautiful but no way my mom would let me have a mouse eating snake