Personally, I wouldn't do anything.  If by chance a notice does show up, deal with it at that time.  Just tell the client you don't want to have to create needless fees for her by filing a return that isn't needed.  There must be close to a bazillion and one EIN applications filled out every year that a return is not needed and never filed.  The IRS isn't going to waste their time tracking down every single one so I wouldn't lose any sleep over it.