the .custom-font-enabled class is only used in this style in Twenty Twelve:
body.custom-font-enabled {
font-family: "Open Sans", Helvetica, Arial, sans-serif;
}
yopu have two choices:
either
add one of your new google fonts directly to the body style in your child theme's style.css;
or
add a filter to functions.php of the child theme to add those body_class again if one of your google fonts is enqueued, plus add the correspondant body style to style.css;
in functions.php (for example):
//add corrresponding body_class if new google font is loaded
add_filter('body_class','twentytwelvechild_custom_font_body_classes');
function twentytwelvechild_custom_font_body_classes( $classes ) {
if ( wp_style_is( 'googleFontsAbel', 'queue' ) )
$classes[] = 'custom-font-enabled';
return $classes;
}
in style.css (for example):
body.custom-font-enabled { font-family: Abel, Verdana, Arial, sans-serif; }
no idea how you are planning to organize that with two custom fonts (?)