Hi there and
to YT! IMO, your baby is only 9 wks and that's how she plays right now and it'll be that way for a while. When Meka would do it at that age, I'd play with her until her bite was too hard..and I let her no by saying "ouch". And she would soften her bite, but if she didnt, I'd make my hand into a fist and say "no" (easier to bite fingers, than a fist) and she would stop. They can understand what you want from them if you teach them. Also, it might help to get her some chew toys to keep her busy
Hope this helps...