It says at the bottom of her site powered by WordPress
That means it's a WordPress.org install.
However, you can create a custom menu on your blog. Pages and posts are different. http://en.support.wordpress.com/post-vs-page/ Pages are static and are for content that rarely changes. They sit outside of the blog structure and they do not automatically update. http://en.support.wordpress.com/pages/
You cannot post to multiple pages in any blog. There is only one main page for posts in a blog and all posts will display on the main blog page. There is no way to exclude posts from the main posts (blog) page.
Though there is only one dynamic page in a blog for posts and we cannot post to more than that one page, we can create the appearance that we have posted to more than one page. We organize posts by assigning categories to them. You can create a custom menu and add the dynamic categories pages created by the software when you publish posts into the custom menu.
Here’s a link to a custom menu walk-through > http://onecoolsitebloggingtips.com/2011/08/11/wordpress-com-custom-menu-walk-through/
There are many common errors, misunderstanding and misconceptions when creating custom menus and you can read about them here > http://wpbtips.wordpress.com/2011/12/19/custom-menus/