Part of the problem is that dogs have bacteria in their saliva that causes necrosis in wounds like this. The bacteria is designed this way so that when they bite a prey animal and it gets away, it slowly dies over the course of a few days from septicemia. I've gone through this with my goats when they were attacked by my neighbors freaking dogs.
I would check and see with the vet that she's getting the right antibiotic. If its just Penicillin it isn't enough for a dog bite wound.
One thing I might do if she were my horse would be to add in some echinacea root to her feed, and help boost her immune system.
You could check at a medical supply place for a dressing that is designed to keep a wound moist yet covered. In my experience a dressed, moist wound closes faster and cleaner than one that is allowed to scab up.
Keep Left Eye's spirits up. Play music, make her feel loved. It might sound silly to some but I truly believe animals and people feel better when they know someone loves them.
Spent a whole hour today laying in a pasture, waiting for a sparkling vampire to show up. Alas, I woke up and looked over, only to find a mound of horse crap. Sigh.