How much are you walking her? My first gsd had severe bilateral HD and I walked her at least 5 miles a day. That helped a lot. She needs good muscle mass pre-surgery because it will help her heal more quickly.
Massie did have a THR but only on one side and I waited until she was 5 years old (she was diagnosed at just under a year). Her recovery time was more like 6 weeks and she was only on bed rest for a little while. I was able to take her on short walks pretty quickly afterwards.
I got her surgery done in Phoenix (was living in Abq at the time).
Ruth & the 4 Legged Rescue Gang
Rafi the malaroo
Gio & Varda, the krazy kittens
....In my heart: