I have just thought of another problem.........

Filesharing..........won't she be able to download this stuff from friends, or sites that would probably not be blocked by policies or parental control software?

It is beginning to look as if the only way to be certain of preventing her would be to remove the software that plays them, and her ability to re-install it. Or block the downloading of those filetypes (but there are ways around that).

As I suggested before, the real problem is that she has been able to access this material before, and is bound to be suspicious when she no longer can. Even if she is not particularly computer literate herself, she must know someone who is,even if that is through a friend, or find someone on a helpsite on the net?

I honestly don't see how you can avoid a confrontation. As she will also probably notice any new software, particularly as most of it gives you a message saying what it has done (so you would need one with a silent blocking capability).

I am afraid that it is really a case of do you want the confrontation now, or later.

Good luck