The Prima Donna WordPress Genesis theme contains the following 3 (optional) menu areas:
1. Primary Menu - above logo area
2. Secondary Menu - below logo area
3. Footer Menu - above the footer widget areas
For more about setting up a menu in WordPress see our WordPress 101 article: Create a Menu in WordPress
Additionally, a Custom Menu widget can be added to the Header Right widget area to create a 4th menu location.
1. Create a menu that you plan to assign to the Header Right are in the Appearance > Menus area.
2. Go to Appearance > Widgets.
3. Drag and drop the Custom Menu widget into the Header Right widget area.
4. Configure the widget as follows: