Look for a NO KILL shelter possibly if you can catch it first See if someone living in the area can keep feeding her. Ferrell cats will survive it's their nature. Cruel but true. Good Luck
If the cat was your mothers more than just for feeding then i would think that this is not a feral cat but just a very skiddish cat. With a little time and patience and food you could probably get the cat comfortable with you.
This is not a no kill shelter, but they do work very hard to try to adapt feral cats to be domesticated. I've had feral cats before and they will do just fine in the wild even with Cayotes and stray dogs. They also hunt mice and birds to feed themselves. Feral cats are survivors
Go to craigslist add pictures and see if someone will take this cat
Post this on Facebook.
Found some babies kitties outside, wild, , fed then. Bad neighbor thew poo in my mailbox and front door,
Those shelters want $100 and up per cat, depending on the shelter.
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