Her fiewstiness might be cute now, but phaving not been socializxed by her mother, I'm just warning you that the fiesty might turn into aggression down the road.
Their mothers begin to teach them how to be a good pack member at around 8 weeks olde. they play with them and scold them if they bite too hard. they roll them onto their backs to teach them submission.
Being a mere human, we don't understand their language, so although we can try to emulate the mother, if we do it wrong, it can cause other issues.
Here is a link to my site, with some exercises to to help establish yourself as the pack leader. She is very young, so strart slowly, but I have done the first 2 exercises with my 7 week old puppies and they have passed every test.
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PS you DO NOT want her to think she is the pack leader. That can cause huge problems as she ages. It might seem cute now, but now is the time to "nip it in the bud"