calamityKate, I think you are misunderstanding me
"I am all for hybrid vigour
A crossbreed isn't a hybrid though?"
A hybrid IS a crossbreed, I was saying that as a rule I prefer crossbreeds, but when it is a deliberate cross of 2 pedigree dogs it's not necessarily going to be as healthy as a "genuine" crossbreed (I know that terminology sounds weird, but I know what I mean!!) I am quite vociferously anti breeding of severely brachiocephalic dogs, but the ones that are already here can't help it, and I have to admit that pugs can have a very sweet nature. I do think more should be done to stop breeding many of these breeds. To my mind if a breed needs corrective surgery to allow it the simple task of breathing and cannot give birth naturally, then nature is telling you something.
OP, your shih Tzu lady does sound a bit "dodgy". Surely if you are irresponsible enough to have an unneutered male and female, and "can't cope" with the resultant 4 dogs, you rehome the puppies rather than your pet
. If she has never been to a vet, the bitch will not be vaccinated, and I would very much doubt she will be neutered either. I really would advise a good rescue. there are many breed rescues out there