Very Agressive Cat, please help
So my girlfriend and I just moved in together. She has 1 female cat, very feral, and I have 2 male cats, twin brothers. We read a lot of information, most importantly Pam Johnson-Bennett's "Cat vs. Cat" about the proper way to introduce the cats in the neutral territory, bought a ton of feliway, had 2 "sanctuary" rooms, everything exactly according to procedure. The cats were starting to get along, but now her female cat is getting more and more agressive, every time she sees one of the boys she hisses and chases them, swatting with claws out the whole way. She blocks off the entrances to rooms, the doorway to the outside, and their food. She even tries to fight them while they are using the litterboxes (we have 3 for 3 cats). I have tried interactive, distracting play and offering treats as rewards for being in the same space and getting along, but it seems like it gets worse every day. What can I do?