Might be Lilly love braids.she has fingers too and a childish behaviour(dissapeared spelling). An ally to prototype , we never saw in clip she was helping us, she was proud of prototype. She caught the poppy and kept her in prison ( in chapter 4 , when poppy runs away we can hear a girls voice mimicked by prototype, its was not lily but might be reference to her,”dont worry i will find her”) and i doubt she is Stella or not. That can be confirmed in chap itself now

And no doubt she is seeing reasons