Help my dogs are fighting!

I have 3 miniature pinschers, all rescues. One is 8, one is 6 and one is 1 year old. The 8 year old, Ginger, has always been a bitch, and she has been with us for 6 years. She has had a few run-ins with our old Miniature pinscher, who died last thanksgiving. The other 2 came to us after Christmas last year, and they seemed to get along ok. But in September this year, out of the blue, Ginger attacked Quinn, the 6 year old. He is such a weenie, he didn't fight back, he just squealed. I tried to intervene, and both Quinn and I walked away with puncture wounds, Quinn had stitches and I had a bruised and swollen right wrist for about 3 weeks, along with multiple puncture wounds on both hands. I went to the Redi-Med for a tetanus shot and they cleaned and bandaged both hands.

Then, last Friday night it happened again. She just attacked him for no reason. He had some puncture wounds on his back, and was extremely sore. Enough to warrant a visit to the vet the next morning, for some clean up, pain pills, and antibiotics. And my husband and I both had wounds.

Then, it happened again this evening. No provoking, no food, no toys, no nothing. Just attacked. And it was out on the porch, and they both went tumbling down the 9 steps off the porch. And so did I. I did get my fingers in her mouth, and tried to pry her mouth off of him. But she has the jaw strength of a pit bull, and I'm not exaggerating. This is a 13 pound dog! Tonight's episode was not as bad, but I just don't know what to do. The only thing I can think of is to completely keep them separate. And my husband is ready to get rid of Ginger. Roxy, the one year old, only weighs nine pounds. If Ginger got a hold of her like that, she just might kill her.

Has anyone had issues like this with a dog before? Poor Quinn, he is just so sweet, and I hate it for him that she is doing this. And I know Ginger has issues. She is almost just crazy. Or psychotic. I don't know. I would be very grateful for any advice?