Here,s my case i'm a Canadian citizen have applied to sponsor my wife who lives in Argentina. i sent application on July 2014. then we got a letter that we have to include her children from her past relationship to her application we got that done. then we got a response letter in November 2014 basically saying i qualify and the file has been forwarded abroad for further processing. now we have received another letter from the mexico visa office to get medical exams, pay the residence fee, and update personal history section 8, 12. also proof of citizenship for our new born twins (five moths) which is already in process. i did get a letter from citizenship saying they will process the applications. since i don't have any proof of citizenship yet what do i do ? will this delay the application process even more than it already is ?