I would advise not trying to help her dominate, in my experience this will likely get her killed. My brother had a cat he wanted to be dominant over the other cats other people in the family owned. He tried to help her be dominant and they turned on her so badly she lived in fear from then on, whereas before she was allowed around them if she knew her place in the group. I have seen people do the same thing with dogs and other animals.
If the chickens have decided she has a certain place in the order, and she is not fighting for a better one, then they are right, and she is unable to be a dominant chicken. If you artificially elevate her status through helping her fight back they will react with greater violence because they all know she is disabled. Cutting her hairdo is about the safest intervention you can make there, and perhaps she will discover an alpha hen mentality when she can see better. Teaching her to fight back, if it were possible, could lead to her becoming a bully instead.
Silkies don't seem to be as punished for their headgear as other chooks with large hairdos, for some reason, I believe due to their usually greater instinct. Animals love and respect instinct in one another, they are predisposed to seek out the most instinctive mates and groups they can as a survival instinct. But some Silkies get punished for their hairdos as well. So haircuts are probably a good idea for them as well.
Personally, I am trying to grow and breed chickens for dual purposes (meat and eggs) and can't tolerate bullies so I cull them; retraining them has failed in the past so I no longer bother trying. I keep a journal recording pertinent facts of each animal (any illnesses, injuries, behavioral problems, parentage, productivity, etc). So if they're bullies when young or any other aberrant behavior I make a note of it and that's one mark against them which means they've likely lost their chance to be bred. They go onto the cull list if it's severe enough. But I have used a few methods in past to deal with them in the short term.
One is the classic 'get a bigger bully' method, where you get a more dominant chicken and hope it tackles the bullies rather than joins in with the bullying. Bit of a gamble there. Another method is to remove the bullies for a few days; this rearranges their place in the social order, and next time you let them out, they will have to work to get their place back and bullying will be the last thing on their minds.
Another method is to incapacitate the bully; either buy chicken specs (I've not used them) or shackle/hobble them (I've done this). You tie a soft, rounded cord around their ankles, not so tight it can cut off circulation, but not so loose it goes over foot or knee; you leave enough length between the legs to allow a normal walking stride but not a longer running stride; and you let them get around in that for a week or so. They will be fine to get up and down from perches, nests, etc, stroll about, dust bathe, etc, but if they try to run after a victim they will fall on their faces. They learn quick with this method.
Another method is to trim the see through part of their upper beak off. It's just like cutting your nails; if you dont go into the non-see-through part it won't hurt. But trimming it close will mean that if they try to stab another bird they will hurt themselves instead. They can eat and drink and preen fine, but not apply great force to another bird in pecking.
Unfortunately bullies are often 'dyed-in-the-wool' and only culling them will stop the majority of them. Best wishes.
