Welcome to BPO. It sounds to me like she has decided she doesn't like her place in your pack and wants to step up to alpha bitch, so to speak. How is the other female handling it? The males will generally tolerate a female alpha and not make too much fuss, the problem will be with the other female, which sounds like what you are describing. Is the problem food related, attention related or just being pushy and overbearing with the other female in general? If there is not major battling, blood, major wounds, etc., I would let them work it out amongst themselves.