The thing that gets me is that in a way Euros had a tragic story here because she has clearly longed for a friend for forever and she wanted that friend to be Sherlock her little brother. So much so that she kills Sherlock’s best friend when they’re kids. I mean her obsession is clearly not healthy and she has issues but I feel like deep down she really did just want Sherlock’s attention.
I do have a problem reconciling what her plan was - especially just the impersonating of different people and being out of Sherringford for quite a while and not setting her plan in the real world? Also that she only escaped recently? None of that makes any sense. Not if we’re to believe she’s smarter than everyone else and persuasive.
But the whole game she plays with them in particular Sherlock is to isolate him in a way. But she doesn’t want him physically hurt? The moment he decided to shoot himself she uses the tranquilizer darts. So it does seem that she does care about Sherlock in her own way. She’s still nuts but I do think she realizes what John means to Sherlock which is why he’s in the well and not Mycroft. This also sort of explains why she doesn’t use her persuasion thing on Sherlock because she might very well want him to make the choice to be her friend on his own. But she doesn’t seem to realize the difference between harming and I suppose playing because she mentions how she thought she was making Sherlock laugh but instead he was crying.