Wow, thanks for all the ideas. A waiver seems quite intimidating, but so does being sued because I THOUGHT my snake would be OK with it. I also have very little experience with mentally handicapped children, so I'm kind of assuming they may be a little more unpredictable than your average 5 year old.... I expressed my concerns to my gf last night, and also said that the children HAVE to have their parents' consent. The more I think about it, the more pissed off I get at my gf. The cat is hers, the snake is mine.
But I also think this could be a great experience for these children as well, and I would love to share my love of reptiles with them. We are rescheduling with the babysitter because I wasn't even going to be home. Thanks for the opinions and ideas, and keep them coming!