Food "aggression"

I have a 2 year old Pit/Dalmatian who I rescued about 9 months ago who ever since we got her has shown to have issues with sharing food. All the dogs have their own bowls anyways, but I'd still like to get her to stop with the "aggression" any advice?

A little more info on her exact behavior because she is a very... unique dog.

With food she will growl and snarl at any other animal that goes near her bowl, but only while she's eating. She's never snarled at me or any other human and doesn't ever snap (try to bite) at any living thing, even when she's growling and snarling into her food dish.

Unrelated to the food problem she has many other personality quirks and in my opinion has a very defined character for a dog, I don't know if her personality is this way naturally or because of the neglect and abuse her pervious owners put her through. I worry if these things are because of the previous abuse that she will never learn there is no need to growl and snarl the way she does... obviously no matter the circumstance she's my baby now and I'll love her even if she always growls over food.