Questions about rose hair tarantula

Hi, so recently I got my adorable rosey (a week ago) and she is currently watching me haha, but any way I have questions about my lovely rosey. So she has been perfect with handling and I did handle her first day I got her she was fine and wasn’t scared but now when I try petting her or even taking the lid off her cage she reacts and gets scared she hasn’t gotten into a defensive pose or bit me also twice while handling her she has spread her mouth and looked as if to bite me i shook my hand to stop her just incase was she trying to bite me? and ive read about molting and she is acting in the way a tarantula about to molt is but I don’t know, if she is a bit scared when should I try to handle her again she isn’t stressed anymore (I think) she has put up webs and has been eating she is a young tarantula about a bit smaller than a hockey puck but I have no idea how old she is does anyone know how old she is?