About to submit our application online, and I see that in the section about supporting documents it requires a proof of citizenship for my wife, such as a passport. Below that it also states that if passports are required, you must bring the originals to your appointment. The problem is that my wife is in the UK and I don't have her passport here in the US with me (I just have a scanned copy). Any suggestions about what to do? Do I actually need to bring her passport to the appointment, or only my own? If I do have to bring proof of her citizenship, would a birth certificate work instead of the passport (since it will be better for her to mail that to me than mailing her passport overseas)? Thank you