Mother Rejecting 5-Month Old Kittens-HELP

Hi,
I live in a rural area and have a cat door. My "house cat" is 22 years old and has renal failure, but not too feeble to contribute to what is becoming a living Hell. So--somebody dumped a pregnant female cat at my farm (a young cat less than a year old). We converted our workshop (inside the main barn) into a "cat sanctuary", ultimately installing a "cat door" with "walkways" along side of workshop when kittens were 8 weeks old. Momma was allowed out of course for supervised periods during this time. Found homes for 2 of the 4 kittens, ended up keeping a girl and a boy. Momma was taken for spaying,shots, etc. when kittens were weaned. EXCEPT for Susie (house cat) everything was fine up until that point. Then at 5 months the 2 kids started to reach sexual maturity. The little female came in heat and we whisked her off to be spayed. Momma and the male kitten got along fine during the female kitten's absence. It was noted however that she had been attempting to keep them apart, or so it seemed. We joked that she didn't want to raise grandkids. We aren't joking anymore!!! Upon returning with the spayed 5-month old kitten, Momma rejected BOTH kittens. Rejection consisted of hissing, acting aggressive, and leaving the farm for periods of 24 hours at a time. The male kitten was taken to be neutered yesterday and the 2 kids are bonded. The workshop (prepped for the winter with heated water bowl and heated pad for the house we prepared for the THREE of them inside the workshop is now occupied by the kittens only. Momma is gone for extended periods, comes back and rejects her children. My aged cat has attacked Momma numerous times, twice requiring antibiotics. Momma wants her home back, i.e., workshop. I didn't WANT to bring the kittens inside because of my elderly cat. Frankly the last 10 days have been too stressful for words. I am apologetic for the long post, just wanted anyone who can offer advice to have as many facts as possible. PLEASE ADVISE, ANYONE, EVERYONE!!!

A big thanks for the kind responses and suggestions. Honestly, I have only recently went on line and read about how cats treat each other in the wild. I wasn't expecting Momma to just want them gone, gone, gone with sexual maturity. I knocked myself out finding homes (indoor homes) for two of the four kittens. Ironically I knew that a mother coon would run off the male baby to prevent inbreeding. I thought cats were indiscriminate and would stay a family. So enough. All are spayed and neutered at this point. It is still a nightmare, though. It will be a harsh winter and it is killing me that momma will have no where to go or will get killed going back and forth between farms. At this point I love all three. My house cat is also killing me slowly. Sigh. Thanks again.

Since my last post, Momma has been around the barn more often, and has been near the kittens, albeit still hissing when one of them gets too close. She has not been attempting to hurt them which had been an initial fear. Also—yesterday Momma was actually throwing herself down in the grass, playing with a corn shock, etc. like her “old self†(just a big kitten). We are working on trying to reunite the family. It is so difficult to be patient, remembering and watching video footage of her raising the kittens. We have decided not to attempt some kind of shelter outside the workshop. The self-contained workshop is 12 ft wide x 40 ft in length. There are two (2) additional lean-to buildings besides the barn, stacks of hay in the main barn, etc. The fact is, when my house cat succumbs (probably by spring) we want to introduce the “family†to the house and the commercial “cat door†leading from main deck into living room. Susie (elderly cat) hates them and Momma is terrified, having been attacked several times. Recently Susie has even entered the barn to set up an “ambushâ€.

The two kittens (Rush and Randi) are recovering from their last vet visits, Rush for his neutering and Randi for post-operative complications from spaying 8 days prior (seroma secondary to a reaction from the suture material). This presented as a herniation (vet agreed) but upon opening the incision found the true condition. So---got to pick both up in separate carriers Wednesday evening still loopy from the anesthetic when released in the workshop. Randi now has stainless steel staples and is antibiotics. We spent three grueling hours Wednesday building a “separate†elevated platform eating/sleeping area with water bowl, cat condo, etc. inside the workshop. We have ordered a separate heating cat bed to fit inside the enclosed cat condo on her new platform. Momma refuses to consider the new area we built for her inside the shop (so far). We have a coon mom and two babies who “raid†the horse’s corn bucket every couple of nights. It took a long time, but the “coon clan†finally figured out about the “cat door†cut in the wall of the workshop. They gorged on dry cat food until they were sick I imagine, then washed their hands. Anyway, now all dry feed is pulled up at 10PM. So I now know about “attracting the wildlifeâ€. This is pertinent because Momma cannot dash in and out to eat 24/7 when the kids are out hunting or sleeping in the hay, etc.

Thanks for everyone’s kind help and suggestions. I am reviewing the info on the recommended links. I am crossing my fingers!