We just lost that beautiful girl in my avatar... her partner is inconsolable, having been with her for his entire life. They are livestock guardians, and he's so depressed that she's gone that he's gone "off duty" and let a coyote come onto the property. We've lost one chicken already that I know of (because now I have 13 orphaned chicks), so I'm hoping he comes around soon. It's only been three days, though, and I know it will take time. I've been spending as much time with Jasper as I can, trying not to emote "sad" energy, which is very difficult, but instead just trying to feel love for him, which is actually pretty easy. Lots of soft talking, a few cookies here and there, and trying to use my happy voice when I can. It's so hard for the partner dog, because the dog that's now gone was such a huge part of their life. The only thing I think you can do is be there for her, be happy and supportive, and let time heal the wound. I heard Jasper barking last night, so maybe he's starting to take an interest in protection again, however, I wish there was a magic wand you could wave and make them all better RIGHT NOW.
Just be good to your dog, try to act happy around her, love her lots, do normal things, and she'll get over it eventually. She takes her cues from you and can read your energy like you read a book, so as long as YOU are happy, she'll become happy. Good luck, I know it's hard.