One of my dogs is due her booster and we are about to take our other girl to stud - is this wise or should I make the dog due her booster wait until after the pregnancy i.e not risk having the live vaccine in the house?

I and I think many others now only give puppy vaccinations and no boosters.  Once a dog is immune, it should last a lifetime.  Titre testing is an option to check levels.  There is a lot of information online especially relating to the horrendous reactions some dogs are having to Lepto 4.
I certainly wouldn't give a vaccine with a bitch due to be mated in the house.
Just my opinion...

Agree with Ells-Bells.

You could take your other dog to have a titre test and see if she is immune - and then she wouldn't need a booster after all (since she probably is immune) and you can forget about it until next year.  If it comes back that she does need a vaccine, then just wait till the puppies have gone.

Find a practice which offers Vaccicheck titre testing - LOADS now do.

If it comes back that she does need a vaccine, then just wait till the puppies have gone.

and don't believe the vet if they say that because it's late you have to start again with two injections

Titre check or vaccinate her - it wont affect the bitch you're breeding (exception being kennel cough which I would hold off on)

The only"annual"booster the non pregnant bitch could be due is Lepto. As this vaccine allegedly only lasts under 12 months it will already no longer be producing antibodies so delaying it a few weeks won't affect the non pregnant bitch