http://homeschooling.gomilpitas.com/articles/031606.htm this might help.

My advice is use one of the big blog services like blogger or wordpress. It is easy to set the blog as private and not listed and to set up comments to come to your email address before they are posted. Then your child can share the address with relatives or whoever they choose but it won't come up in search engines. Our child has had a few blogs over the years and it has been a good way to get writing experience.