Miranda, I certainly don't think you have failed with her. I don't know what it is about rawhide, but some dogs that are sweet as can be 100% of the time will get possive of rawhide.

You are doing the right things. You have and continue to establish yourself as alpha, and take it away from her when she growls. And as Dixieland Dancer said, if she doesn't start to get the message, you may just have to eliminate it all together.

As a reinforcer, it may help to put her onthe "nothing in lifeis free" program...make her perform a behavior before she gets anything....make her sit before you pet her, Make her lay down before she eats her dinner, etc. This will reinforce that all good things come from you, and really strengthen your bond with her.