Well there is nothing you can do if your mom won't let you.

If she's acting normal, she could be fine. She may just have diarrhea from it. But let your mom know chocolate is very toxic to dogs because it contains theobromine and theobromine is very, very toxic.

However, milk chocolate does not contain as much theobromine as, say, dark chocolate, or baker's chocolate. It would take more milk chocolate than baker's chocolate for it to be toxic for a dog.

Here are links to more information:
http://www.netpetmagazine.com/articles/choc.tox.html
http://www.talktothevet.com/ARTICLES...olatetoxic.HTM
http://www.vetinfo.com/dencyclopedia/dechoc.html
http://www.petalia.com.au/Templates/...&story_no=1390