Wow, your fiance doesn't want you to travel alone? REALLY?! It's to FLORIDA, which is about 80 miles from the Bahamas

A trip that could have been made any time to get her spayed, or to get your male neutered. They have low-cost spay/neuter clinics all the time here in Florida, a little research online could have told you that. Google is your friend! If you can't handle a trip like that to get help for your baby, what are you going to do when she's giving birth and gets a puppy stuck? What if she doesn't make it and you need to tube feed any surviving puppies?
Your vet sounds like a real gem