You can't "wait and see." You need to erect a physical barrier asap. A small dog might not be able to enter, but a cat could, or a small critter.
I don't quite understand the layout of your home, but you really need to erect a solid barrier that she can't hurl herself into so that it can be knocked down and she goes flying off the edge again. GSDs have strong prey drives, and we can't leave this to chance or even, a strong bond with us, their owners. It takes years of training before we can be assured that our dogs will ignore prey that's running away when we command it.
If you are unable to erect a barrier, your dog needs to be crated at all times when you can't physically control her. And by that, I mean, tether her to you, or to heavy furniture while you're there supervising her.
I'm sorry if this sounds a bit harsh, but your dog can be hurt, not just from a fall but from what happens after it. You adopted her to give her a great life, but the first step to that is protecting her and ensuring her safety.