Run it occasionally
It will probably solve her problems.
There is no doubt that the porn sites are a problem but kiddy sites like cartoon network.com are at least as bad. If she has kids using the computer she should tell them never download flash games etc. they are packaged with many of the worst offenders.
Downloads of various browser plug-ins, media players, weather bug, Kazaa, Bonzi Buddy, etc. are packaged with adware.
I installed a Microsoft mouse recently that had an invasive program in it's software. I think adding the adware allows them to sell the product cheaper.