Any advice on animal hoarding?

My mother is 92 years old with major short-term memory loss and other dementia issues. She didn't really like cats when I was young, then in her 80s or so took a liking to them. For a while she had 3-4 cats, and did very well with their feeding, vet visits, and other needs. It seemed as she approached her late 80s and the dementia set in, she believed that having the routines with the cats is what kept her going. Using that sort of logic, she attracted stray cats into the yard by putting copious amounts of canned and other food out. By the time I arrived to help look after my mother's needs, there were at least ten cats. She was not getting them fixed or vaccinated and took no steps to control fleas or worms. They were inbreeding and rapidly expanding in population. It was out of control and when I tried to discuss with her to take steps (trap/neuter/release, etc) to get a handle on the situation, she shrieked loudly that I was trying to kill her. Someone heard that and called the police...who saw the situation and had animal control come remove the cats. It is simply impossible and has been for years to have any reasonable discussion with her. The animal control folks asked if I thought she should keep any. I suggested that the three cats who had lived in the house and were more domesticated and attached should stay and I would take good care of them. When they asked my mother, she said "just get rid of all of them" out of stubbornness. Which they did. By the end of that eventful day, she had forgotten the police were there. I went and rescued the three from the pound and brought them back. One got sick, and had diarrhea all over. My mother did not even notice. When I told her he needed help, she said "tough...cats die". I took it to the vet and after a few days there pulled through. So, that was in 2013. I am quite attached to the three cats and have kept them indoors, flea and worm free, give them good company, etc. It has been a constant struggle since 2013 to keep her from repeating the situation. Every day she puts food (people food...I took over all the cat food and keep it locked up) outside, and makes little shelters for cats in hope that a cat will have kittens etc. I am not against cats. I fell in love with those three and consider them mine. I have volunteered at cat rescue shelters. I have had to put extra locks on the garage and stuff as preventative measure. My problem leading to my question is that I am feeling like I have to be here almost all of the time to keep the flood of cats from coming back, and after three years it is getting really tiring. The animal control said if they have to come back all the cats are going and I will not be allowed to bring those three back. The animal rights type people in this urban area cannot take many cats in. Even if they take all cats my mother will actively attract more if she can. She wails that I have ruined her life because I try to control it. Anyone else have to deal with pet hoarding?