Poor Grace. I just feel for you. Lucy was attacked on a walk on Xmas eve a couple of years ago, and had drains and staples and looked like a Civil War soldier in the infirmary. Did the vet say if it was all surface damage or were muscles involved? I'm hoping her collar took the brunt of it, so your new collar was worth every penny.
After Lucy was mending, Diesel slept near her and followed her to make sure she was ok. So brothers aren't all bad... Lucy was a shy and spooky girl who lived in my closet that first year we had her, and over the years she has blossomed into a pretty outgoing silly girl. Some people have told me she's dominant too, and some of that could be because of her experience. I'm always a little apprehensive when she meets a new dog, but I try not to let that travel down the leash. For the most part, she gets along with everybody and wasn't afraid of the boys I fostered.
Don't worry too much about Grace being afraid. Our dogs take our cues from us. So for now send Grace calm healing thoughts and I'm sending you a big huge hug.