This is a problem, but it is not as serious as a fear aggressive dog. It does take some time, and will require some changes, but your GSD needs to start seeing your husband as her provider and caretaker, and things will change.
Every time he comes in a room with her, he needs to toss her a treat. (Do not try to approach her at first, as this will probably scare her and she will be afraid to eat the treat.)
He needs to be the one to feed her.
He should be the ONLY one to take her out for a walk.
How long is this going to take? I cannot tell you for sure. Some dogs get over this problem in a few days, but some take weeks or even months. Eventually she will see your husband as "that guy who gives me a treat" and look forward to seeing him everytime.
This works with deliverymen too. If your dog is barking excessively or is scared of the postal carrier or UPS guy, you need to give them some treats so that they give her one every time they approach your house.
Again, they should toss them from afar, and not scare her by trying to hand a treat to her.