[gaijingirl]

I think maybe next time she tries to play in her water bowl you should try a different reaction. By yelling at her, you may be reinforcing a negative behavior. I think I would try to not give her attention for the behavior, but calmly ignore it and distract her in a different way. For example, you could have a treat handy and call her over to you and reward her for coming to you and leaving the water. If you can do this with a clicker, that is even better, because that will help reinforce the good behavior.

She may be doing this partly for attention. I know that if there is a time that my dog thinks he needs attention that he thinks he is not getting he will grab the nearest thing he can find at his level that does not belong to him and run. The "stealing" game gets him attention. It might not be good attention, but it is still attention. I have handled his little thievery game by not getting up and going after him and chasing him around to get it back (because that is the fun of it for him and reinforces the bad behavior) but, instead I ignore him for a few seconds and then calmly go and get a toy he likes or ask him if he wants a treat. He'll then drop the item, I say, "good leave it!" and he becomes more interested in the new thing. He gets rewarded for leaving the bad behavior.