Hi Sorry for the delay
Bring everything and anything that proves you are a couple and living together etc Bills, Bank Statements, Insurance policies etc
they would have liked to have original documents and ones that go back 6-12 months so that shows you have been and still are together.
they made a point of asking me for my tax return (i file seperately so didn't think it was of interest to them) but it would again show that i was "married" but filing on my own but it would my spouse name and ssn etc on it.
We also brought more recent photos and they kept some.
hope this helps and best wishes.