When you create child pages, they are not automatically set to appear in the Section (navigation) Menu. If you want your pages to appear in the section menu, you must complete the following settings in the Site Design manager or on the Design tab in page edit mode.
From the System Menu, open the Site Design Manager.
From the Site drop-down, select the site to configure pages for.
In the Page List, select a page by clicking Edit beside the page name. The Page Design Details dialog appears.
Check the Include in Section Menu checkbox if you want this page to appear in the Section Menu (the left or right sidebar, depending on your site's design).
Clicking the Save and Apply to Children link will do the following:
If the parent page’s “Include in Section Menu” check box is checked, all children’s “Include in Section Menu” check boxes are reset to Checked.
If the parent page’s “Include in Section Menu” check box is unchecked, all children’s “Include in Section Menu” check boxes are reset to Unchecked.
Settings are only applied to the direct children of the page (children of the children are not affected).
Clicking the Include new Children in Section Menu checkbox does the following:
The “Include in Section Menu” field of a child is automatically set to Checked when the child page is created. Hence the child page will be displayed on the Section Menu after creation.
If the “Include new Children in Section Menu” field of the parent page is Unchecked, the “Include in Section Menu” field of a child page is also Unchecked when the child page is created. Hence that child page is not shown on the section menu.
Click Save.
You can also perform steps 4-6 on the page's Design tab while in page edit mode.
Repeat the procedure above but in Steps 4. and 5., uncheck the check boxes.