I have paper ready for my parent's GC application. before I mailed it out, I found out that I need my parent's marriage certificate. I had my bother went to Min Zheng Ju to ask for a copy because they lost it long time ago. But the Min Zheng Ju guy insisted that my parents need to go in person. My parents' visa has expired, so if they go back go China, they cannot come to US without new visa. Their I94 will expired soon.
My question is, if I submit I-130 without my father's marriage certificate now, and submit it later upon request of INS, will this delay or cause the denial of the application?
Or should I wait till I get a copy of some proof of their marriage?
Or should I submit my mother's application now. Or should I submit them together, then I have to delay my mother's application becuase no marriage certificate situation?
Thank you.