Since the animals are obviously suffering, contact your local Animal Care & Control department at your town/city hall. If you can go there with photo's of the animals, that would help too.
DO NOT under ANY circumstances put yourself in harms way with thiese animals. They are unsocialised, probably in alot of pain which makes them very unpredictable, they are likely to have infestations of fleas and ticks (both of which will transfer to you and can cause significant illness for you), there is also a very strong possibility of mange (Sarcoptic and Demodectic) - Sarcoptic is HIGHLY contagious to both other animals and humans. Then you have the more serious health issues of cancer, AIDS, anaemia, Parvovirus and leukaemia....and the worst of all, Rabies.
All of the above health issues are extremely common in hoarder animals, not all are treatable and many will spread to your other pets and you and your family. This makes you basic allegery to cats VERY minor in comparison
Get in touch with the authorities, they know how to handle these situations safely and securely.
Many a good intention has ended up in tragedy, so let those who are trained get on with dealing with these animals. As someone who worked alongside these agencies, it is heartbreaking to see the animals suffer but you NEED to take a step back and let them deal with it. Hoarding is so commonplace, I have seen it too many times myself and it breaks my heart every single time and every single time all I ever wanted to do was go give the animals a cuddle.....but I knew that cuddle had the potential to not just make me very unwell, but could actually kill me if that animal bit or scratched me.
So PLEASE let the professionals deal with this. You have a good heart and the best thing you can do for the lady and her animals is get the authorities involved as soon as possible and step back and let them work with her and get the animals to safety....even if that means euthanasia cos at least they will not be in pain anymore.