No, you do need to interfere. She should not have food aggression to humans. You should be able to take her food away, pet her, etc. without any ill effects.
I found this online, and it is helpful. I don't necessarily agree with the pinch or prong collar but the rest is good
Dog Food Aggression Training Techniques
Firstly, be careful. If you believe your dog poses any real physical threat to you or family members I'd advise getting professional help. Speak to a professional dog trainer or animal behaviorist.
Below is a list of training techniques which could help your dog overcome his dog food aggression. Remember all of these techniques are designed to work towards reconditioning your dog to enjoy having you around anytime. Mix it up, show your dog who is boss.
* Hand feed your dogs, even stick your hands into your dogs bowl while he is eating.
* Stroke and pet your dog while he is eating and at the same time talk to him in a calming tone. All you are doing at this point is showing your dog that it is a good thing for you to be around.
* Stand at a distance your dog is comfortable with, then gradually reduce this distance over time. You can flick a few treats in (or near) the bowl as you slowly reduce the distance.
* Put your dogs bowl down with nothing in it, your dog will look back at you as though you are crazy. He'll then literally beg you to come over and fill his bowl.
* Feed your dog as normal but hold back a few pieces of his meal. When he is finished licking the bowl, he'll look back up at you, then you can come over and give him the remaining food.
* Drop a few of your dogs very favorite treats into his bowl each time you walk past it. After a while of this your dog will welcome the sight of you approaching the bowl.
* When your dog is eating, call him over to you, when he gets to you reward him, make it worth his while then let him back to the food bowl.
* While you are preparing your dogs meal put him in a down-stay or sit position, only release him from your command once you have put his bowl down. By doing this you are controlling meal time and establishing (or re-establishing) your role as your dogs leader. To learn more about how to be a strong and respected leader I recommend Secrets Of A Professional Dog Trainer.
* Work with another family member on this technique. Put your dog in his collar and leash and have him sit with your helper while you prepare the food. When you are ready release your dog and allow him his food. Again you are controlling the situation.
* Try the Trade Up Method. What you do is take away the food or toy your dog is guarding, and replace it with something better. You can use an obedience command such as give or leave it to encourage your dog to release the precious resource he is guarding. You then take this resource (the food or toy) and give the trade up item to your dog. Once your dog has finished with the new item, you can then give back the resource you took away. This technique proves to your dog that he will receive something great for giving something up, it will recondition his thinking.
* Every time you are with your dog have him in a pinch or prong collar with a leash attached. Whenever he displays any signs of dog food aggression you immediately administer a correction to your dog by snapping on the leash. What this does to your dog is build a negative association to the act of his food guarding antics. Note: I personally don't advocate this method but many experienced dog trainers swear by it.