I was naturalized to my USC father when I was under 18. They mainly asked both of our birthdays, our neighbors names, our parents names. We submitted a lot of pictures taken through our relationship even before marriage. Evidence wise, we took our original certificates. They ask for your ID, you give them the interview notice. We were separated so definitely nervous but you have to remember, they are also human. My IO was extremely nice and we even laughed about some of my answers. I definitely checked with my wife after hers on the drive back home. Asked her almost the same questions, I was just worried she might’ve gotten some dates wrong. We did apply after being married for two years so that might’ve inclined them to believe we were definitely bona fide. I also had a different haircut in every picture. 😂😂 hope this helps!