I would try some classical conditioning. If you have ever read Jean Donaldson's "Dogs are from Neptune", she has a whole chapter dealing with this type of situation.

Get some really yummy treats (chicken, hot dogs, steak pieces - whatever she likes a lot). Either take her to the park or our for a walk. Whenever she sees another dog approach and starts being a little aggressive, start feeding her tasty tidbits (BAR IS OPEN). When the dog leaves stop feeding her yummy treats (BAR IS CLOSED). Keep repeating this over time with dogs getting closer and closer. You want her to associate other dogs with great things. It doesn't matter if she is snarling or growling at the other dog - all you want to do is establish the association of OTHER DOGS = GOOD THINGS.

As far as her being food aggressive with your other dog, I would just feed them separate, and make sure they understand that you are the one that controls the food by making them do behaviors before they get dinner. Sit or Down or Stay.

Good Luck