That's what I dont understand the woman we gat her from said her mother was not like that she actually encouraged her puppies to eat from her food when she was weening them she was real genital. Our dog leia is never with out food never showed aggression towards while she was eating I started with her real young to ensure she wouldn't be like because we have kids in the house.That’s very serious. It’s probably severe food aggression/resource guarding, which is trainable, but when it has gotten to this point you really need professional help. It could also be some more serious mental problems, which may not be fixable. You need urgent help especially since she’s a danger to her puppies and also everybody around her. For now, never let the puppies be around when she’s eating, take her to a different room to feed her. Don’t let food, bones or toys near the mother and the puppies. Never leave then unsupervised, always keep an eye on them.
It’s also important that you pass on this information to the new owners of the puppies, they need to know this since the same or similar behavior is likley to be inherited.
What kind of breed is it? Does she have other problem behaviors?