This code adds a widget to the genesis nav menu which you can populate with the Genesis eNews Extended plugins widget.
The CSS makes the input form and submit button small enough soit doesn’t increase the default height of the menu.
The code works for the primary menu however you can use the code for any nav menu simply by changing primary to the name of your menu in the PHP code.
Tested on the Genesis Sample child theme by StudioPress. CSS may need tweaking for use on other genesis child themes.
Here’s the code: