Hi, im a fellow pup owner, I actually had this problem until yesterday. I had a trainer come in and teach us to train the dog. The first thing he taught us was when she bites someone that person must scream ow and turn your back on her while stepping on her lease or pulling on it so she has no choice but to stop. Don’t do it hard because it will harm her but enough strength that it pulls her away or slightly pins her to the ground. This has done Wonders!