The Wayward Children series by Seanan McGuire. They're all novellas about teenagers who are dumped back into the 'real world' after living in fantasy worlds they tumbled into. Some of them are kind of "save the world" or "save the small world of people I live with" or "save my family." So I'm not sure it's quite what you're looking for, but it definitely has a unique set of teenage protagonists who are more well equipped to do some actual saving.