<human>: Could you distill the essence of the text into 1-3 sentences?

So, I have a German Shepherd, shes 1 year old, she's the sweetest dog I've had, she is very kind to people, loves everyone, shes fine with people being near her food, taking things like balls away from her, anything, But I have this problem at parks, not with people, even random people could grab items from her and she is fine, but if another dog tries to grab a ball from her, she will growl and sometimes snap at, or bite another dog, and this isn't okay, As I'm worried the other dogs will get hurt, especially little dogs (also worth mentioning if there is no toys or balls or anything she is fine with almost all dogs, she will run and play with them)

Is there anything I can do to help get this behavior to be not as aggressive, or should I just avoid being around other dogs playing with balls all together?
<bot>: Dog is sweet, very friendly to dogs and people, but if another dog tries to take a ball away from my dog, she will snap, bite, and growl at other dogs. is this something I can fix?