so it seems to be going well. If buster goes out of sight marbles will often go check on him, or if i am holding buster she will come up wagging and sniff him up. only time she gets mad is when he nips at her face or feet. I know this is fairly normal for puppy play but i think she might just be to old for it. should i let her correct him with a good bark/growl or should i be pulling him away to tell him play time is over when he does this? She's never taken a nip at him, just usually shoves him down, growls and walks away. he however doesn't seem to get the hint. any idea's