Howdy.

just set her limited account up, lock it up nice and tight. And preconfigure firewall etc so that it won't co-operate with the p2p program.
She will download it, but it's no good if she cannot install it. as her account does not have high enough priveleges to do the install.

And if worse comes to worse then just install Emule . just preconfigure the firewall to not allow the needed tcp connections, an thus it will make her downloading of pirated software less enjoyable, as it will take over an hour to download a 3mb mp3

cheers
f2B