Out of my 3 young kitties, the male, who is larger, has already been neutered [about a month ago] but the two girls [who are substantially smaller] are not yet spayed. Molly is the older one [from a diff litter than the other girl] and is apparently in heat; she is being affectionate, making her calling/chirping noises and assuming the mating position. We were already planning to spay her [and the other girl] but we wanted to wait to they were a little larger which they are now, but the soonest the vet could get Molly in to spay is Dec 13th [about 3 weeks from now roughly]. Will this bother her to wait this long? This is my first time experiencing a cat in heat.