So sorry to hear about your dog.
Firstly, your vet would not have done the operation if he did not think there was a very good chance of recovery, so don't beat yourself up over letting her have the op.
A week is a very short time to see any improvement, the bruising etc. needs to go down first and that will take a while.
She has had a massive shock to her system and needs time to recover in peace and quiet in her own home. Give her lots of cuddles and make her feel safe and secure (which I am sure you are doing!).
Be careful about giving her any supplements or herbal medicine (don't forget herbal stuff can have side effects and is as powerful as most medicines) I would check with your vet before giving her anything as it may counteract things he is prescribing.
Is she on any medication?
A good site to post your question (it is a rescue site for GSD's but there will be people on there that have more experience of this sort of thing) is:
http://s10.invisionfree.com/biggsd/index.php?a ct=idx