Hi grahama, good luck with Peanut when she arrives, we got Scooby when he was 10wks so he was quite old really, the advice from our vet was that if we were confident that the other dogs/puppies were up to date and Scooby stayed on our garden it was quite safe for them to mix, and mix he did !! He had friends round often and I think it did him the world of good, he's 9mths and a well socialised and happy dog, so go for it.