Take her to the vet? She may have issues with eating/absorbing the food or something.

Can she do those little dog biscuits? Or just nothing but pork?

She's probably a bit ropey bless her if she's had such a hard time. We used to have a cat who had her kitten at 6 months old before we had them (rehomed with me together). Although they were only 6 months different in age the mother was very visibly ropier healthwise than the kitten.

Either way you are a bloody soft touch, I'm the same. No way I'd take a stray person in but any old animal.