[Ciera's mom]

I am needing advice on how to stop Ciera from biting. She just chews on your fingers when you try to pet her or when you are playing with her she will try to find your fingers to chew them. It really hurts sometimes and I have tried holding her mouth and telling her no bite, but when I let her loose she goes right back at it. She likes to chew on my son too, she will play with him and bite his fingers and his feet and it really hurts him sometimes. He won't do anything to her because we have taught him not to hit her and to be easy, but he cries because she hurts. I saw that someone said to try and hold their jaw like and keep your finger in their mouth where ever they move and that will make them get tired of it and stop but she will stop after a min and when I let go she will just start biting again. What can I do??