See our puppies were taken too early from mom and haven't learned to control their bite. And they both are very stubborn; mother was belegin shepherd and very stubborn. My brother's dog doesn't mind his wife--bites and nips at her. My puppy bites and nips at my 82 yr old mom. She bites me too. I don't want to hurt her; I've been told that I need to "show her" who is "boss"; you know what I mean I'm sure and I don't want to do; afraid it'll make her mean and aggressive.
Take this for what it is worth, I have had 1 dog, experience limited. My pup was taken from his mother at 7 weeks. I tend to think this contributed to him being an extreme land shark. What works for one person may not work for another. My husband could make a fist the pup would try to bite it and he would say no bite and the pup would stop. Only a couple times was he on the receiving end of biting fueled zoomies.
I on the other hand struggled. We always had the puppy on leash in the home while holding it and always separated the pup from our children via crate or expen. They did have supervised play only when the pup had the appropriate energy level. You should do the same with your mother, meaning restrict access to her from the puppy. Make sure your puppy is getting a good amount of exercise they have tons of energy. They need to run and explore in safe places.
I had a rule. No one interacts with the puppy unless you have a toy. Have a couple toys the minute the pup bites redirect to the toy and play with your puppy with the toy. You can't watch the puppy or play with the puppy, it's crated.
The other thing I did after much research was bite inhibition. People told me alpha role the puppy, show the puppy who is boss. Worst advice imo for my experience.
So using what I knew about my puppies energy I chose times and I let my puppy bite me. Over the course of several months the force of biting and amount of biting become less to none and it was a bonding and learning experience for us. At 9 months my pup is very respectful with his mouth and knows it can cause pain. If he accidentally gets anyone during play he is very sorry will lay at your feet or kiss your hand.
There is no need for conflict. Your puppy is not stubborn it is doing what it was born to do. It is your job to teach the puppy.
Between redirection to toys and bite inhibition my problem was solved it took time, consistency, patience and educating myself.
There is a bite inhibition sticky in the puppy section and search the internet using common sense come up with a plan that can work for you. Also the other advice in this thread is good to.
This is just my experience, which is very limited, but it is what worked for me, with out conflict.
There are also many things you can do with training treats to overtime teach your puppy to take food gently from your hand.
It takes time some longer than others.