I have 3½-year-old identical girls. We have never dressed them alike or called them twins; we've tried hard to raise them as individuals. Still, I believe one feels less loved than the other, resulting in her acting out more.
Sister A just seems to be a mama's girl. She follows me around and enjoys helping me with whatever task I'm doing. Of course we have our days, but in general, we enjoy each other.
Sister B really needs her sister. She needs to wear the same “kind of clothes,” and goes nuts if she thinks her sister is not being treated fairly by someone. Often, she cries if I punish her sister! On the other hand, she hits and pinches her sister and me often. Sister B also seems to lack common sense. Example: if given three choices of fun things to do and only one thing she cannot do, she'll rebel and try to do the one thing she's not supposed to do.
I know they can use more separate time, but that's difficult. They're in the same preschool class but next year they'll be in different schools so they have some space. Have you found a question in any of this? I hope so.
I can find a question with no difficulty; a good answer may be harder! But as a mother of twins, I will certainly try. It sounds as though Sister B is really struggling to find her own identity. That may sound like psychological jargon (which I usually manage to avoid), but I can't think of a good synonym. It is as though, in her developing mind, she somehow overlaps with her twin sister—needs to have on the same clothes, hurts if her sister is punished, etc. She finds part of her own self in her sister. I could reverse that and say that she finds part of her sister in her own self and hasn't quite got this sorted out in her own mind. Chances are Sister A has some of the same tendency but just doesn't show it so obviously. This kind of behaviour is very common in identical twins. But how can it be otherwise in two beings who look and sound so much alike? Certainly I saw some of it in my twins, who were not only not identical but were boy-girl fraternals. I'll give you an example. My daughter was obviously "ready" to walk more than a month ahead of her brother. She would stand holding on to the foot rail of her high chair, just waiting to move out. Her brother, shaky on his feet but an excellent crawler, would repeatedly speed across the room, grab her by her nappy, and pull her down. However, once he was "ready" to walk, he somehow said "Go ahead" to her, and they both walked. He never again pulled her down. The point of my story is that you can expect a lot of this sort of overlapping and undifferentiated behaviour.
As for the pinching of Sister A and of you, I think it is part of the same struggle. Sister B, who doesn't quite understand how she and Sister A differ, seems to perceive her twin as more competent. And probably she sees you as more accepting of Sister A. So she strikes out occasionally at both of you. You have put your finger on one of the needed remedies: do as much with each girl individually as you possibly can. Next year's school arrangement (only a few months away now) should be helpful.
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