Even skint people have to eat.
Get your young guest to help you cook a meal. Let her choose from a range of options and then go shopping together for the ingredients. (Remember to appear to let the junior 'chef' take charge of things). Then let her do all the cooking (while you keep an unobtrusive eye on things, of course!).
All 10 year olds respond well to being treated as grown ups and most of them (both boys and girls) love cooking and getting praise for what they've done.
You can heap the praise on by presenting your guest with a certificate (signed by you) for being a brilliant chef. Of course, you shouldn't simply print off the certificate yourself; you should allow your guest to design it on your PC. If you've not got a suitable DTP program, download Seif PagePlus SE, for free, here:
http://www.freeserifsoftware.com/software/Page Plus/default.asp
Chris