There's several things you can do to work on food aggression to humans, but it is a bit trickier when it is towards other dogs. When its with other dogs, usually the best thing is prevention. As others have said, she will learn to deal with the crate or she just won't be able to have her special treats. It is a huge concern that she is doing that, especially at such a young age. I would probably never trust them alone (unsupervised) together. You might get to that point someday, but for now I'd just plan some major preventative measures so that Beanie doesn't get hurt.. or worse