I am so sorry you are going thru this I am sure its hard to watch two dogs you love tear each other up. Unfortunately I am afraid once it has gone "there" escalated to a full blown fight the odds of this being trained out of them are not good. They are not fighting because they hate each other its a dominance thing. I am pretty sure this will continue I think your only options really are rehoming one of them (preferably a home with no other female dogs) or finding a way to let them live separately in your house I know its hard to give one of them up but this situation can be very dangerous for the humans in the house as well as a serious injury to one of the girls. I have always had opposite sexes in the house so I have never had this happen. I hope you can find a good resolution to this problem wishing you all the best!