Deae friend,
May God bless you for taking her in!!
No, they will not vaccinate a pregnant cat BUT she can be tested for FELV/FIV and even xrayed.
I would take her to a vet and get those tests done.
I hope all will be well.
Warmest best wishes,
Terri
Feline Healthcare Expert
Expert in feline health and behavior. 20 years experience with cats.