Looks like it preys off of idiots just like your little sister. I could see how she fell for it. Everyone knows installing little stuff like that is the easiest way to get viruses and you should explain that to her.
I did some extra research and you have the Adware.Myweb.Funweb product thing that is distributed through their products. You shouldn't ever download from that site, and anyone who visits that website should stay away from all downloads.
http://www.liamdelahunty.com/tips/fun_web_products.phpThere's some extra info.
Also, I removed the link since apparently it has browser hijack programs on there.