I question the legitimacy of this particular posting. I do not feel that there is added security of using a keylogger. Yes you can draw the analogy of a security camera, but do you need to view everything?
Another thing is if you make a record of something, someone else can get their hands on it. it does not matter how secure the key logger is, or how secure the computer is. If you write it down, someone can get it.
I do not feel a keylogger is a good way to keep kids safe online. The best way is to watch what they are doing. If you have young kids you should be in the room with them. If they are teenagers, this will only serve to break down the relationship between the child and the parent, and they will find other ways to get online, or a way around it.