With a little luck it should be OK. Vacc to preg are touchy, the kittens may get hurt. But the most dangerous here are the living vaccines. Rabies are (usually) a killed vaccine, and thus, less dangerous.
Best is if you phone this vet and ask... You wont have 100% safety, but less to guess.
Thank you so much...I took in a stray that showed up on my porch, low and behold she was pregnant. luckily between me, my best friend and family we will have loving homes for kitties and mama . I have always had cats/dogs/horses etc but always spayed my animals...thus is a first for me. I called the vet this morning. Thank you so much for your reply!