It all depends, they will grow at different rates as some are early developers and some are late developers.
I think you should take WV~Yorkies advice and ask the breeder if you want an idea.
Also her stools shouldnt be runny if they are you need to try her with a different diet or visit your vet.
Poppy used to get a mucky butt but since I changed her food to something more natural and started to add dry food in with her wet her stools have been much better and she dosnt need a butt wash half as much as she used to
