I'm going to describe what my puppy was like, it seems similar to yours in some ways. This is how he was, now he is fine and enjoys walks.
so he would cry and whine as soon as we started up the drive way, and when we were moving a few houses down he would stop and sit or lay down. at first I thought he was tired but if I started moving back to the house he would get up and lead the way. also, if he saw a car or people in either direction he would suddenly want to get moving again. I used to give in but he would then have so much energy at the house I started deciding I would make him walk since I knew it wasn't because he was tired.
so the first thing I tried was walking ahead where I wanted to go, and if he lay down I would walk until the leash was extended and wait with my back to him. this was pretty effective I have to say, he hated being ignored and he would run over to me. so it was kind of start stop start stop start stop but the stops got less and less and then he stopped the silliness altogether.
sometimes these days he'll plop down and want to roll in grass or flowers or chew on a stick, which is fine but when he starts spending a long time with me standing there I just start applying more and more pressure on his leash. I didn't want to apply this pressure to his neck so I got him a body harness. that way I can pretty much lift him to his feet on the occasions when he ignores a moderate pull.
so I definitely get you about a dog having no energy one way, and a bundle of energy going back home. your dog is older and may not care if you turn your back but I would try that first. if she doesn't care if you stand with your back to her for long times then get a harness and simply pick her up and pull her a little. don't pull if she's only wearing a neck collar.
my guy is 1000% better than he was a few weeks ago and now positively loves going for walks.
also, definitely check out what more experienced GS owners post
Tiger A.K.A Clown Town- 12/19/13