A couple of things I should point out.
The last time I let her use the PC and she found herself on that ---smurf-poo--- was when I got tired of sitting there "monitoring" her browsing and I walked into the kitchen to make a sandwich. Or it was a burrito. Something. In any case I figure I was in there for about ten minutes when she started asking her mom about this and that.
There really isn't any point in explaining what is and isn't acceptable and actually expecting her to remember. Without going into too much detail, this is a child that completely forgets what we're talking about five minutes into the conversation but can recite every lyric in Justin Bieber's Baby.

Don't get me wrong, I will, and have, explained what is acceptable. I just don't expect her to remember any of it.
Porn, nudity, sec and all the related stuff is a concept this child is just now grasping. She finally figured out last month what it is, exactly, mommy and I do behind the closed door at midnight.

We're just now getting into the monthly bleeding thing.
Chat of any sort is already off limits.
If she "signs up" for a site and/or alters an existing password and fails to update me on that fact, that website is going right into the blacklist.
It's a little weird trying to pull all this together. I've have always been about creating a network with FULL unadulterated access to anything I please while creating defensive layers at preventing the outside from compromising the network. I have never, in all the time I've been on the net, ever considered designing a system at protecting itself from the INSIDE (except websites and they're an entirely different ball game anyways).
Thanks for the suggestions.
I am a little leery at installing yet another service app that I'll personally never use.