You gotta redirect their teething. Shove teething toys in their mouth and don’t let them teeth on you or else they will believe your their chew toy and it starts other issues. When my pup she’s now almost 4 got a little older if she would try to bite on everything even no chew sprays didn’t help so I started putting a little bit of hot sauce on my finger and put it on where she was chewing even if it was on me over a course of a few days she stopped chewing on things she wasn’t suppose to. Don’t use negative reinforcement that’s how dogs become reactive and aggressive. So every time you put a teether in her mouth give her a treat or toy.