I just posted a youtube video link according to the directions and searched the help files. The link shows up as a link on the blog rather than as an embedded video. The blog is http://adhdchildren.wordpress.com/
Thanks. That’s what I suspected. We cannot help you here at WordPress.com with that site as it’s not being hosted by WordPress.com and we run on different software. This is the correct forum for your software http://wordpress.ORG/support/ If you have not registered a WordPress.org username account yet you can do so on the top right hand corner of the page I just linked to so you can post to those support forums.
WordPress.com vs WordPress.org: The Differences http://support.wordpress.com/com-vs-org/
Best wishes with your site.