Help with is_page() and calling css for specific pages in a Child Theme

The first parameter of wp_enqueue_style and wp_register_style is used to register the stylesheet for later use. So, you can register it early and later call it just specifying it’s first parameter.

In this case you are registering and enqueueing the stylesheet td-theme-child, which file is style.css. After that, if the conditional passes, you are registering and enqueueing the stylesheet td-theme-child, which file is style2.css… but, WP already sent the td-theme-child, so the style2.css will never hit the browser.

So, in short, just change the first parameter of your style2.css enqueue line:

wp_enqueue_style( 'td-theme-child2', get_stylesheet_directory_uri().'/style2.css'. 'c', 'all' );