Yeah, I fell for the old 'can you cash this check for me' scam myself. Not only do you get stuck covering the check and fees, but most likely her father was charged the $30 or so returned check fee. That's $200 you and her father paid so that they could get high...quite the scam really, especially when they know they won't suffer much, if any, consequence from it.
No, you can't divorce your child, but you can learn to say no and mean it. Took me a long time, but my AS doesn't even bother trying anymore after I just started saying no as a complete sentence. (I learned that handy tool right here on SR