Her house is her property, as are her cats. So no one has the right to interfere unless she wants them to. Your "help" is not help if it isn't wanted.
A person who abuses animals may not be a person I would trust, and may not be a nice person, but they are within their rights. You would also be within your rights to shun an animal abuser, of course. However, in her mind she may have been loving those cats rather than abusing them. And even if she dies due to her choices, that is her right. Your life is yours to do with as you please, even to the point of destroying it. Her neighbors were not even aware of the abundance of cats, so no one claimed she was harming their property in any way. No one had a right to lift a finger to make the woman change her life in any way. Still, people being people, some were concerned for the woman and the cats.
So what happened?
Well, the person who discovered the situation asked the woman if she really wanted that many cats in her house. She said she did. So he asked if she had enough food for them and for herself. She admitted she was having to stretch food to make ends meet and keep everyone fed. He asked if she would like some help providing for the cats. She said she would.
He asked if she would mind if he asked around to see if people might be willing to help her with some food, and she agreed to the suggestion. So word went out. People donated cat food and made meals for the woman. A few even stayed to help her clean up a little, after making sure she didn't object.
As it happens, she has now given away about half of the cats to various willing adopters. People who would come to her home to deliver food they were donating would see a particular cat they really liked, and the woman would usually let them leave with that cat. The extra human interaction seems to be reducing her "need" for so many cats, too. Her house is a lot cleaner, by comparison to what it was before. Her health problems have cleared up, and she is seeing a doctor once a week right now. He comes to her home every Thursday afternoon to check her progress. A local veterinarian even donated feline birth control. The woman's life, and the lives of her cats, looks to be improving.
A couple of concerned neighbors still feel the woman may have mental health problems and are trying to keep in touch with her more than they had been before. If she asks for help, help is there. If she doesn't ask, and if she rejects it if offered, then no one has any right to judge how she lives and what makes her happy. I wouldn't have it any other way.