Your profile (what people can see if they actually click on your username) is only available to other members, but your username is public. I understand wanting to make your internet footprint a little more private - that's one reason my username is not my real name (though I chose it more because there were about eight "Heather"s around when I first joined!).
One thing I'm planning to add in the forum policy revisions coming out in the next few months: could everyone put your first name or whatever you would like to be called in your signature like Christa has done. I know many of us chose usernames simply because so many accounts have been made over the years and most names are taken. I'd really like to be able for us to call one another by the names we prefer. For the record, I answer equally to "Blythe" or "Heather".
Sorry to hijack your post, Christa

. Let me know if you need help changing your username!
Oh - just wanted to add that your signature - where you currently have your son's full name - is viewable by anyone visiting the site. There is nothing wrong with that, but if you want to be a little more private you can change it.