sorry to hear of your catten problems! Usually it's all about persistence and takes months for things to settle but in some cases it might never settle. Have you tried some of those (unfortunately expensive) cat calming plug ins? I am considering them at the moment as our 6 month old is beating up our 2 year old constantly and making her feel and look terribly upset.
Do you ever tell her off when she instigates fighting? Just an almighty hiss and clapping from you could make her realise you do not like what she is doing and you are the boss.
Other than that I'm not really sure! There are also medications the vets can offer but I've never resorted to that myself.
Hopefully things will get better for you soon