A professional trainer is definitely what she needs. I don't know how old you are, but like otch1 said, you're obviously not in a position to make the decisions for the dog, your parents are. No matter how much you want to help your dog.
The dog needs to see a professional trainer/behaviorist, In order to find the real problem and real solution. Otherwise, it sounds like you could possibly have a liability on your hands. For example, your dog is out walking with you, and slips off the lead, or maybe gets out of your yard. If your dog is truly aggressive, or dominant aggressive, then she may go attack somebody or something that provokes her unintentionally. Or possibly somebody could corner her accidentally, if she's fearful aggressive. Then you have a lawsuit on your hands, where you lose lots, and lots, and lots of money. And your dog will be put down.
Perhaps, maybe you can take a video of your dog doing what you're describing, and then somebody can try to analyze it here? That would be no replacement for professional help, but it's better than nothing.
The dog needs to see a professional trainer/behaviorist, In order to find the real problem and real solution. Otherwise, it sounds like you could possibly have a liability on your hands. For example, your dog is out walking with you, and slips off the lead, or maybe gets out of your yard. If your dog is truly aggressive, or dominant aggressive, then she may go attack somebody or something that provokes her unintentionally. Or possibly somebody could corner her accidentally, if she's fearful aggressive. Then you have a lawsuit on your hands, where you lose lots, and lots, and lots of money. And your dog will be put down.
Perhaps, maybe you can take a video of your dog doing what you're describing, and then somebody can try to analyze it here? That would be no replacement for professional help, but it's better than nothing.