that's a tough one Brie, sometimes re-introduction works, sometimes, not... the only experience I have was a bantam cochin who had been injured by a rooster. when I brought her in to heal, she went broody on me... so I gave her some eggs. when they hatched and she was all healed, I moved her into the broody pen until her chicks grew out to be as big as her (chicks were LF) re-introducing her was easy, because there were 4 birds, not just one, so it helped spread out some of the behavior. Now that broody is Mama to a good %age of my flock, she is pretty high ranking for a bitty thing.
you may have to keep her separated, being bottom of the pecking order won't likely change for her...
Or, if you have just one or two aggressors, you could try separating them for a few weeks... taking a bird from the top places them at the bottom, at least temporarily... when they go back...
if you have the space, and are inclined to try... you could see if she would take over as lead for a younger group of chickens...