Most young dogs are voracious eaters and the survival instinct takes over.
The quicker they can get food into their stomach, the quicker it is out of the reach of others.
In the wild, food may not be available for some time. I assume you are using treats to reward your puppy, so why not use a stroke of the head and a ‘good-girl’ instead?
The focus would switch from food to you. When she eats quickly at meal times you can gradually introduce control by making her sit and wait for her food.
If you must use treats for training then close your hand in a fist round the food. Present this to her and only when she waits, open your hand and let her take it.
You are not expecting too much by any means, but you must only reward gentle behaviour.
Never let her succeed when she is a hooligan.