It's amazing what people do. I wouldn't doubt she was dumped, good thing she found you before she started to suffer.
My coop kitty, shortly after we caught her. She's a vicious hunter but doesn't equate the carcasses to food.
You may want to have shave her belly and check for a spay scar, we have a cat that showed up very pregnant. She's going to the humane society tomorrow to supply the ever growing cat over population we have here. We also have a cat that showed up in January, she was a walking bag of bones and...