Incorrect Date of Birth on Fiancées Passport

[Cesar & Duong 1]

My fiancée's Duong passport is incorrect on her passport that I submitted a copy of with our fiancée application. This is due to a clerical error on her national identity card that was made by the local authorities in Vinh Long. Her incorrect date of birth is September 15, 1990 but her correct date of birth is May 19th, 1990. I heard that it is common in Vietnam for local authorities to make errors in identification paperwork such entering someone's date of birth incorrectly. Our plan is to wait until our application is reviewed by USCIS and hopefully approved without a RFE and sent to the Consulate in Ho Chi Minh City to fixed this. We intend on getting a notarized statement from the local authorities in Vinh Long, correcting her national identification and passport and take all of this to her visa interview at the Consulate in Ho Chi Minh City. Has anyone done this before and how long does it take to complete all of this?