Copy header.php into your child theme and change this:
<nav id="site-navigation" class="main-navigation" role="navigation">
<h3 class="menu-toggle"><?php _e( 'Menu', 'twentytwelve' ); ?></h3>
<a class="assistive-text" href="#content" title="<?php esc_attr_e( 'Skip to content', 'twentytwelve' ); ?>"><?php _e( 'Skip to content', 'twentytwelve' ); ?></a>
<?php wp_nav_menu( array( 'theme_location' => 'primary', 'menu_class' => 'nav-menu' ) ); ?>
</nav><!-- #site-navigation -->
to this:
<nav id="site-navigation" class="main-navigation" role="navigation">
<h3 class="menu-toggle"><?php _e( 'Menu', 'twentytwelve' ); ?></h3>
<a class="assistive-text" href="#content" title="<?php esc_attr_e( 'Skip to content', 'twentytwelve' ); ?>"><?php _e( 'Skip to content', 'twentytwelve' ); ?></a>
<?php wp_nav_menu( array( 'theme_location' => 'primary', 'menu_class' => 'nav-menu' ) ); ?>
</nav><!-- #site-navigation -->
<?php if ( ! dynamic_sidebar( 'sidebar-aweber' ) ) : ?>
<?php endif; ?>
And put this in your child theme’s functions.php:
function child_twentyeleven_widgets_init() {
register_sidebar( array(
'name' => __( 'Below Navigation', 'twentyeleven' ),
'id' => 'sidebar-aweber',
'description' => __( 'An optional widget area below the nav menu', 'twentyeleven' ),
'before_widget' => '',
'after_widget' => "",
'before_title' => '',
'after_title' => '',
) );
}
add_action( 'widgets_init', 'child_twentyeleven_widgets_init',11 );