Then she will not be able to come over anymore because her parents will think he's being mean to her. He'll still win.
Essentially if he seems very busy they'll stop her from going over and bothering him. Everything else simply needs to be locked down, with simple reasons like "I lost it somewhere around here" or "It's broken so I sent it in for repairs". Don't even mention the lockbox and hide it somewhere. The computer stays locked under password until you can finish "cleaning it of dangerous viruses".
She'll clue in eventually of course but the parents will remain oblivious, if she tries to stop you from reading tell your parents you can't read and catch up on studies because she's bothering you. Nail in the coffin right there, education goes well beyond everything else in importance, always. This is a last resort though since then you'll have to read periodically when she's not around as well to complete the "faking" process. Of course you may also simply read not fake it and take it seriously as well, recommended as per usual.
This is what I did with my annoying cousins I had coming over a long time ago. I simulated the most boring house visit experience ever, nothing was happening at all. They didn't want to come over anymore after a few visits.
