When she was with her mom and littermates, they all taught her what was acceptable. If she played too hard with her brothers and sisters, they would yelp and stop playing with her. If she bit her mom for attention, her mom would push her away and pay attention to another puppy. Now that you're the leader, it's your job to show her that biting is not very fun and doesn't get her what she wants.
When you're training your Great Pyrenees to not bite, you need to be firm and you need to show her that biting means the fun ends and she doesn't get attention. Never yell, scream at, or hit your puppy for biting. Though she will grow into a big dog, she'll always be sensitive and yelling at her could harm your relationship. The best thing you can do is spend time with her, be consistent with training, and strengthen your bond.
With practice and patience, you will soon break her of the biting habit and you can get back to having fun together. Below are three methods you can try. Read through them and pick the best one for you and your puppy.