Great questions. First...it is never too late to get a cat spayed if she is healthy. Eight is not that old for a cat and the spaying surgery is done so frequently it has minimal risks associated with it. In fact, spaying your cat could help prevent further problems. Older unspayed cats are prone to a pyometra (infected uterus) that can be extremely serious. Cats do not stop going into heat at a certain age like a person would, so this could go on for some time. I would recommend giving your local shelter or animal control a call to see if there are any low-cost spay/neuter options in your area.