She knows just enough to be frustrated at how easy it would be to make a mistake.
The - dream, editor, whatever you'd call it - showed up for her a few weeks ago. She knew enough not to ignore it, but not to make more than the tiniest change, either, and now she has a tiny butterfly tattoo, plausibly enough just an odd bruise, on the sole of her foot, and a deadline, and no idea how long the deadline gives her, or whether she'll have any warning before she loses her chance forever.
It's been two weeks. She can't wait much longer; even if the deadline itself isn't too close yet, they're starting to notice that she's distracted, stressed; if they decide she's misbehaving, and drug her, she won't be able to do anything at all, probably. Not a risk she can take, anyway, not on her one chance at freedom.
It's hard to get to sleep - it's always hard to get to sleep, she's never properly tired at the right time even if she's exhausted - but knowing that tonight is the night helps, a little.