She starts calling herself "Tab", for short, not that anyone calls her anything apart from Kers. She writes suitably encrypted emails to Aelise about ideas for fixing the world - mostly she asks questions, to start, forming a picture of the exact problem she has to solve.
She misses her parents, but not very much. At least she got to say goodbye.
When her brain won't absorb new information, she bounces around in zero-g.
After six months, Aelise visits again.
Tab says, "Anybody you store up here must be important somehow. If I don't know about the other secret person, I won't know how to come up with ideas that work with them being important however they're important."
"Aelise thinks that if something happened to Chelsa here people would start having wars again. I'm supposed to think of a way for that to not happen, and then Chelsa can go away here too."
"The other Chelsa wasn't doing her thing to the whole world," says Harley. "Just a little piece of it. It was the other you who killed her," he adds offhandedly.
"Wow." Tab isn't sure if she believes this story, but it promises to be fascinating. "There are vampires in that world? And my - mirror universe twin is the empress of it? I bet she isn't seven, though. How do you know I'm her?"