I'm getting ready to file AOS for my wife .We already have a approved I130 since 2005 but I was just a green card holder ;now I'm a citizen so we are going to send a copy of approved I 130 with the rest of documents nedded to aos.Do we have to include a cover letter to upgrade the petition from F2A to IR or that is only necessary if the petition hadn't been approved yet?I'm a bit confused.