The phrase "missing girls" refers to girls who cannot be found or are lost. It could be used to describe girls who are missing from their families or girls who have disappeared without any knowledge of their current whereabouts. Full definition
My daughter puts these sneakers on with everything and we're talking about miss girl - girl that would rather walk around in a dress and high heels than do anything else. (thefashionablehousewife.com)
They help them express their feeling towards missing their girls when they are away from each other for some time. (template.net)
The newspaper is closing down amid an expanding police investigation of phone hacking into missing girls and grieving families as well as celebrities, and the alleged press bribery of police officers for information. (canadianbusiness.com)