M.M.
Hi P., Try using the "Big Girl" method. You know, "Big girls don't suck their thumbs" etc. But don't be too hard on her. My daughter had the same habit. First I got her to only suck in private at home. Then down to only when she was going to sleep. The thing is it's a habit. She probably doesn't even realize she's doing it. Once I called attention to it, my daughter weaned herself off it. And I didn't have to be the bad guy. Hope this helps! And remember, a thumb is better than a pacifier. Even if she goes on sucking her thumb 'til she's six, it's not THAT big a deal. Good Luck! M.