"She needs to watch for the sales and buy a WHOLE chicken, cut it up and make it stretch 3 meals."
And boil the chicken first, so she can get chicken soup out of that bird. And close her legs so she doesn't have any more mouths to feed.
Boiled chicken served with steamed rice is my son's favorite meal.
Other cheap sources of protein-rich food -- canned tuna, eggs, and milk, which is double-cheap when you buy it two gallons at a time (good, that is, if you're not lactose intolerant, which THANK GOD I am not ... I drink about a quart a day).
What? And dry up her source of income?