My 2 months old is suckling on her left thumb. Can this form a habbit later ?? Does it deform her teeth/jaw? How to make her stop?

A. No no it’s a common habit for kids to break the pattern you just have to keep taking the hand out of the mouth every time because if you continue to do so or allow the child to do it then it will create a problem of constant sucking otherwise it’s not going to create problem