Some kids just need something in their mouths...not a big deal and she will probably out grow this (my friend's dad did the ol' tabasco on the thumb trick and it worked). I didn't want to use a pacifier for my baby, but she definitely needed one....but she is still little and I will wean her off that eventually...(6 mos old). When I was growing up I used to put my hair in my mouth, bite the sides of my cheeks, bite my nails and chew on pencils and tons of other things probably....fortunately, I never over-ate...but I did smoke for a few years...when I was an adult I quit biting my nails and needed a replacement oral fixation I guess, but I quit that too...so now I am conscious not to over-eat...and have not 'replaced' any of my fixations so far...but I am in my 30's, so it took a while! I never had any issues at school or socially, so I wouldn't worry about it. She is only 6 so I'm sure she is normal and just fine.