What do you mean "her guests"? Anyone who stays in your home is your guest, not the guest's guest.
Did the woman who booked this include the other people on the reservation and pay for them? If not, what are the doing staying in your home?
The person who makes the booking is supposed to be one of the people staying, otherwise it is a 3rd party booking, which isn't supported by Airbnb.
My advice is to get these people out of your house- cancel the booking. Contact Airbnb to cancel the rest of this reservation without any penalties to you if you can't find out what's going on with this booking and get contact info for the people who are there. And 3.5 months? You realize that establishes tenancy and it could be a serious hassle to try to evict her or whoever is staying there?
@Judi804