What I would do is create different post categories, and have each blog page display posts for its own category. If you look at the posts on your Blog page, for example, you’ll see that they all have the category Uncategorized. Create a category called Thought Fulls and another category called Book or Mom*Me (or some other appropriate name, although I’m not sure you can have an asterisk as part of a category’s slug). To define your categories, go to Posts > Categories from the admin dashboard.
Then go back to your posts and assign one or the other category to it, and uncheck Uncategorized. Create a new post for “Thought Fulls” that contains the current content of the “Thought Fulls” page.
Finally, go to Appearance > Menus. Hopefully your theme has support for WordPress custom menus. If not, I would strongly suggest using one of the themes in the WordPress Theme Directory that does (like TwentyThirteen). If your theme does support WordPress menus, then click on the link that’s labeled create new menu, give it a name (like Main_Menu), and click Create Menu.
On the left, you should be able to add menu items from the Pages section (Home and About, in your case), and then you can add menu items from the Categories (Thought Full & Book). You can drag the menu items around to whatever order you want, and you can even change the text of the menu item (if you wanted the menu to read “Blog” instead of “Book,” for example). Click on the Save Menu button. Click on the Manage Locations tab and make sure your new menu is being used for your theme’s navigation menu.
Now, when a user clicks on the Thought Full menu item, they’ll get a list of all blog posts with that category, or if they click on the Book (or Blog) menu item, they’ll get a list of posts for just that category.
