Suzanne

For Genesis child themes that output HTML5 only.
This plugin adds an entry field just below the title field on all post, 
page and custom post type edit screens. It allows you to specify a 
subtitle for the content and then outputs the result in an H2 tag just 
under the entry-title where you’d expect to find it.
This plugin is for use with Genesis HTML5 child themes only because it 
uses the hook, genesis_entry_header to position the output after the 
title but before the post-info.

Genesis Subtitles

For Genesis child themes that output HTML5 only.

Eduardo Zulian

This plugin simply adds a subtitle input field to all your widgets. Once you fill out this subtitle field, it’ll automatically appear right after the widget title.
Inspired by <a href="https://wordpress.org/plugins/dp-widgets-plus/" rel="ugc">DP Widgets Plus</a>.

Widget Subtitle

Add a subtitle input field to all widgets.

Genesis Subtitles vs Widget Subtitle