I agree with KYS that Since you are the boss, she should not be growling or snipping at you. period

In a way your dog does not see you as an Alpha, therefore she's not worried of any consequences when she growls or nips your skin. That is really serious and you need to stop that behavior as soon as possible.

My son's retriever, Lady, was about 3 months old when she started growling at my 2 1/2 year old grand-niece, whenever my grand-niece would get near her toys or food bowl. Here's how I cured that:

The minutes she growls -- I don't care who it's to -- in the crate she goes with a loud "No growl" or "No nipping" (whichever the case may be). After putting her in the crate, Lady would see ME give my grand-niece her toys and let her pick up her food bowl and hold it for a while. Ten minutes later, I would let her out and ask my niece to gently go near the toys; now, at this point, Lady was looking at me and all I said was "be nice". It took probably one week for her to learn that my grand-niece (at 2 1/2 years of age) was an alpha over her as well (although I would never leave them alone without supervision).

The same thing with feeding her a treat; it was very painful because she was very rough grabbing it from my fingers. Any time her teeth would touch my skin she would get the same command -- and IN THE CRATE SHE GOES! It's not that she hates her crate, it's just that dogs hate to be ignored, and I would turn around and ignore her for a few minutes. When I give Lady a treat now, she is ever so gentle in taking it from my fingers. Let us know how it goes