To answer your question..... yes the way the owner handled the pups played a huge huge part in what is going on with your pup and considering the conditions, its genetics as well.
Take a look at this page .. LAT
Using that method can help your dog learn to tolerate the different things that are causing the fear. Your main goal is to work with her at a point BEFORE she begins to show fear whether it is 10 feet or 50 feet. Use absolutely the best yummiest treats you can find for her. This will be hard work and she'll earn every best tasting bite of it
If she reacts, move back to a point before she reacted and begin again. If you are using any kind of corrections during this, stop.
If you post your general location, someone on here may know of a good behaviorist relatively close by that you could contact. Or you could try locating one that is very familiar with GSD. They would be able to teach you how to work with your dog and help her work through these fears.