Congrats.
Sounds like the puppies will be beautiful.
Ask your vet, but peppermint salve (avail. from places like FiascoFarm, and maybe also Hoeggers) might help that troublesome double teat. It sounds like she has mastitis there? Pepermint salve is used by goat and cow dairies in the event of mastitis. Keeping the teat empty, "milked out" will help too.
I have something else, to say, but not sure how to best put it. We currently seem to live in a world where "SAFETY" is almost something like a religion, and the talismans for it are professional certifications, special rules about responsibility, and proceedures. Even up well into the 1970's, the world didn't work that way. Somehow, humanity survived to get where we are today. Dogs did too, and many were well bred then, without the insistance on certs, vet visits, and spay/newter. Life is not always ideal, but we can do our best with what we have.