Added Google font – not showing in drop down in Theme Options

Hi,
I’ve seen a lot of posts on this, and even a couple about this specific font, but I can’t seem to get this to work.

I have this in my child theme functions.php:

add_filter( 'avf_google_heading_font',  'avia_add_heading_font');
function avia_add_heading_font($fonts)
{
$fonts['Rokkitt'] = 'Rokkitt:400,700';
return $fonts;
}

add_filter( 'avf_google_content_font',  'avia_add_content_font');
function avia_add_content_font($fonts)
{
$fonts['Rokkitt'] = 'Rokkitt:400,700';
return $fonts;
}

But the Rokkitt font isn’t showing in the drop down in Theme Options for either the heading or the body font. I would greatly appreciate a point in the right direction.

Thanks!