The Late Crew and the Copy Cat Creature

Alisha Alva just wants teachers to treat her like a normal human being.
Yes, her (super cool) mum has mental health issues she calls her Letters. And yes, staying up late helping Mum on Bad Nights sometimes means it's hard to keep her eyes open in school.
But surely if Alisha acts like a very normal perfectly proper girl, her head of year Miss Penn will finally leave her alone.
Oh, and don't forget the aliens. Last term, Alisha and her friends the Late Crew met extraterrestrials. Now, a new out-of-this-world creature is following Alisha. A creature that can become a copy of any living thing it sees.
It might be that nothing is ever normal again...