You should probably get her taken to a vet just to check out about hephatic lipidosis. Essentially, if the cat was overweight before the previous owner died, she could now be in a downward spiral where she doesn’t eat and her body canibalizes itself, very inefficiently, destroying her liver. Once that happens you essentially need to forcefeed a cat or have a feeding tub put into their stomach.
I know you don’t want to be scared, but a cat not eating for that long would worry me and we once lost one of our cats to hephatic lipidosis because we/the vets didn’t recognize the symptoms in time.
He was having mouth trouble, and managed to bite on a kibble in a way that caused him so much pain he went and hid for a whole day. I dug him out, took him to the vet, and they gave him medications to help with the infection and with the pain – but he was still so traumatized he just wouldn’t eat. I had to take him back to the vet a day later and they showed me how to force-feed him.
It sounds like some kind of torture but really all it is is using a plastic syringe to squirt wet food into his mouth. There’s special prescription wet food that’s easier to eat (and easier to put into the plastic syringe for force-feeding) and extra-packed with nutrients to help get a cat back on its feet nutrition-wise. After a few messy sessions of wrapping him in a towel and force-feeding him this food, he realized his mouth wasn’t hurting anymore and decided he’d much rather eat the tasty food without my assistance.