I would separate Goldie from Cuddles right now for at least couple of weeks, if you keep them separated she may not pluck her when you put them back together, but it is a hard habit to break. If you want to keep Goldie or Cuddles away depends, Goldie may start plucking another one of the chickens if you take Cuddles away, if she does you need to keep her separate, if she doesn't you can keep Cuddles away. I would try to separate the coop into two sections where the separated bird(s) can see and interact with the others, otherwise you may have problems when you try to reintegrate them. I would try to up their protein % of their food and see if that would help, and give them other things to do, a bale of hay where you toss a couple flakes in the garden every couple of days will help keep them busy.
It does sound more like Goldie is doing it more as a bad habit than because she is lacking something, so I would be prepared to either keep the two of them separated, rehome one of them, or try something like Pinless Peepers or Bumper Bits, which ever you can find over there.