You have an obnoxious teenager dog who is checking to see if she can run the 'pack' in her new home. All pups get pushy at this age so don't panic!
She is bite inhibited or you would be seeing serious bite wounds not just bruises or a painful feeling when she grabs you. This is good as it means you just need to change the little mistake she has made about who the leaders of the pack are.
There are ways to teach her she is not the leader, and that you are, that involve no violence so she should not be triggered to act aggressively. Around the house a new set of rules will go in place for her to get what she wants. She will have to say 'please' by doing something you ask her to do before she gets petted, fed, let out, or in etc. You can read about this which is called the nothing in life is free program here
www.goletavet.com/nothingfree.html
I also strongly suggest you contact a trainer to find a positive type obedience class to join in your area so she can work on some new attitudes.
www.apdt.com may help you find one in your area.
I also suggest not just putting her in the yard for exercise. Instead some of the time throw a ball or frisbee for her, take her for a leash walk, practice obedience commands. Tire out her mind and body a bit and that will help you too.
It does take work to put manners on an adolescent puppy but I think you will enjoy her lots more once you do.
One thing you can try to stop her when she grips you - if it does not work on her stop using it.
If she puts teeth on you or your clothing YIPE in a high pitched tone like she would if you stepped on a tail by accident and see if she lets you go and acts surprised. If she does you can fold your arms and not interact with her for a few moments as 'punishment'. She might react perfectly as it sounds like she is bite inhibited. If however she growls and bites harder this is NOT something to use with her. Telling her 'owe that hurts and I won't play with you if you do that' in 'dog' might mean more to her than any human 'growling' in your reprimand voice.
Hope this helps you!
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