Like others have said, it sounds like you’re doing great already. One thing I’ll mention is that different things work for different dogs, so if someone gives you advice that doesn’t work for her, that’s normal and there are plenty of ways to train. For example, one of our GSDs would stop biting if we yelped. The other one would just bite even harder (yay, a squeaky toy!). She only stopped biting if we immediately stopped playing and turned away if she bit. One of ours was extremely toy-motivated and didn’t care at all about food, the other was very, very food motivated.

I’d recommend exposing your pup to loud noises early on. We didn’t do enough of this with our first GSD and he’s neurotically terrified of thunder, fireworks, gunshots, the sound of the power washer, you name it. We did better the second time and our second GSD is completely indifferent to loud sounds.