Just don't give in when she growls at you. If she growls at you, and you stop whatever "offensive" behavior caused the growling, she has won, SHE has made YOU do what SHE wants. And in the mind of doggie - if something works . . . do it again!
Same goes for when you put her on her back . . . YOU have to decide when she gets up. If SHE decides, SHE is in charge. You can't let her go until she submits to your authority (suddenly hearing Cartman from South Park in my head
). This has worked like a charm with my bossy princess . . . no spanking necessary.