Her doggie has developed deeply conditioned responses. It is very much akin to cellular memory in a human to maintain a remnant of a prior trauma, so that even when cleared from memory and the consciousness, the body cellular structure, having a consciousness of its own, may perpetuate some symptoms. The dog is associating the presence of other dogs with an inner need to go on the defensive. Healing is underway for the traumatic deep karmic issues underlying this strong aversion. That will take time. In the meanwhile, conditioned responses like this have a life of their own that will fade over time if it is not rewarded. Unfortunately, the dog here cannot understand any human coaching that the concerns are unwarranted about the approach of other dogs. So this is a harder behavior to extinguish when it is running on autopilot. This is likely to fade over time with the healing underway, and there may be opportunities for deconditioning this fear reaction. It might require the help of a dog trainer, but is not impossible. While disconcerting to the human observer, this is within the normal repertoire of dogs to display as they are often easily aroused and will respond with vigor to most any kind of stimulus. It is not harmful to them in that sense, more so to the bystanders who are exposed to the menacing behavior. When the dog has no future clashes that lead to bloodshed, this will help the behavior to fade. In the meanwhile, this is a back-and-forth tug-of-war because the dog is reinforcing the conditioning. Each time she menaces another canine and gets away with it and nothing bad happens, it will seem like a victory and ample reason to conclude she did the right thing and to keep it up as a defense. That is what you are dealing with now, the inner fears have lessened, but the conditioned response to keep up the defenses has not.