
I agree with theemx, u dont want her gettin to big to quickly as this can have some nasty effects later on in life, ie hip dysplasia and alike.
have owned numerous Rotties as well as GSD's, as long as vet says she is coming along ok then there shouldnt be a problem, she's probably a bit on the small side due to breeder not having full knowledge on weaning etc, as u already thought yourselves.
Good luck with this wonderful breed

Nicci