Her argument for taking possession isn't a bad one. This laptop is white, shiny, has lots of buttons and plays music and films, therefore it's a toy, stupid.
I vaguely babble on about needing to use it to write something or to check my email and she gives me a withering look as she stuffs another Atomic Kitten CD into the disk drive and draws big Barbie-pink patterns with the art software.
This has taught me an important lesson. Even though, in a school setting, we always emphasise the educational benefits of using a computer, for a child, its appeal owes much to the same instincts that make them want to play with a toy. For them, the great barrier between playing and working just doesn't exist.
As adults we don't like to admit this. We like to talk about ICT in terms of efficiency and productivity, accessing the curriculum in new and imaginative ways. But we don't like to say that just as a child enjoys pushing a button on a doll to make it talk, so computer users get a kick from clicking a mouse and getting something to happen.
I've been thinking about this as I look around the staff room. My colleague, The Buff, is a great techno-enthusiast. But to be honest, he's like one of those people who are always fixing their cars but never drive them anywhere. He's much more interested in fiddling with the software than in applying it to anything useful. And if you stripped back what he's really doing, it's playing a problem-solving game.
Toys can also be status symbols. When I see Mrs Gatsby, the headteacher, taking her laptop to a meeting or a conference, I often think she enjoys carrying it and opening it up as much as using it. For her, it's saying: "I'm the kind of modern professional that carries around a laptop."
I'm not knocking them for this because I admit to succumbing to the toy-shop appeal myself. When I was checking out which machine to buy, I was influenced as much by feel as functionality. I confess, I was seeking the laptop which would be the most fun to use.
I know we're not meant to think this way about computers. The sales information is all very matt black and macho, talking about memory size and operating systems. But it would be much more honest if we accepted that grown-ups like to play just as much as children and we're as likely to want to play DVDs and burn CDs as to get to grips with a spreadsheet.
How many times have you been in a school or an office and seen tens of thousands of pounds' worth of computing power being used by someone to play desktop solitaire, which you could play with a packet of cards that cost a couple of quid? Even when we're meant to be working, it's difficult not to start playing.
It's not just games that distract us. You've got the laptop so you can be flexible about where you're working. No longer will you waste a long train journey looking out the window. With a laptop, you can really put the time to good use.
Except when you open up the laptop, you watch the screen shimmer into view and think: "Hmmm, not sure about that desktop background colour. It's a long journey, I'll just try another shade." Then for the next hour you scroll through every pattern and picture available. And when that's finished, you start adjusting the mouse speed. Or you start looking to see what the time difference would be if you lived in Mexico. Five minutes later, your train arrives at the station and you haven't even written a word. As Hamlet once said: "The play's the thing."