One interesting thing I didn't give any thought to was that Emma (Heidi named the foster) cannot hear a warning growl from another dog. Earl is getting crabby with other dogs in his old age, so when Emma climbs on top of him to play, he gives her a warning growl to back off. Because Earl is older and I know he doesn't want to deal with a puppy climbing all over him, I move her off of him and she usually saunters off.
Kayden has been VERY patient with her but she plays very rough (as many puppies do) and he has had to correct her a few times.
It would be interesting to know if she can pick up on the vibrations of the growl prior to the correction and whether or not the pairing of the two will help her to learn to back off when she picks up on these. I think it probably makes things confusing for her because most dogs are vocal and play growl when they are playing. Then again, the body language is usually quite different between the two. Then again, play can often quickly escalate into a fight...
Thoughts?