Millie Bobby Brown

You're talking about three multi-talented young actresses - but you're leaving out a fourth - Ava Kolker - and she is multi-talented as well.

http://www.npr.org/2016/08/19/490671346/stranger-things-creators-on-barb-eleven-and-how-glitter-delayed-production

On Millie Bobby Brown's performance as Eleven

Ross: The thing about Millie and what makes her so incredible is most child actors, even the good ones – even, we're talking, like top 1 percent or top 0.5 percent, like the best of the best — what they're still not great at is listening. Because that's a very difficult thing, to stay engaged in a scene when it's not your line, because a lot of child actors are just waiting for the next line. And obviously that does not work with Eleven because this is a girl ... who doesn't have, she has no lines, and so all of it has to come off of reaction. So to find someone that is able to convey that sense of character and really to be talking without talking, that's a hard enough thing for an adult actor to do, a trained adult actor. But for someone who's, you know, 11 years old is just — you know, Millie, it's almost freaky how good she is. ...

I remember when Shawn Levy was directing his mind was blown because she went up to him and was like, "Can I do another take?" No other kids are doing that. And then you're like, "OK, but the last two were great." And she's like, "No, let me do one more." ... And then she does one more and she just takes it to another level. And that's something that, yes, I might expect from David Harbour, who's been acting his whole life, or Winona Ryder, but for that to come from this 11-year-old girl is truly incredible.

And also because she's very — which is something else that most child actors don't have — she's very aware of the camera. So someone like Winona or David, they know how to play to the camera. They know when it's in close-up, they know when it's not. But most child actors, they're doing the same thing take after take after take. They're not adjusting their performance to lens or they're not adjusting it to camera position. But Millie absolutely is able to do that, which is another reason why she's so incredible and I think why she's able to communicate so much without saying very much.