It's so hard to know. It's encouraging that the vet wasn't concerned. If the puppy is significantly smaller than she should be for her breed, I would be concerned about why that is. They grow so rapidly at that age, I'm not sure comparing to Baxter is useful or not. I just saw an irish wolfhound puppy at the store on his first outing and he was HUGE.
Rosie has a congenital cataract (at least I think that's what it is, my memory is so flawed) that wasn't picked up until she saw an opthomologist for a different eye problem . The regular vet didn't see it. At least I think that's what it was/is. He explained to me that she was born with it and it wouldn't interfere with her functional vision unless I needed her to read fine print.
She catches frisbees/treats/balls with great accuracy.
So, long rambling reply to say--I have no idea. I hope she'll be ok.