I would agree with this. I could write an affidavit saying I knew you, but what would that prove?
photos are very strong evidence. Do you have some from your wedding? With friends and family on too? That’s excellent if so - especially if some had to travel out of country to your wedding.
honeymoon? Receipts (plane, hotel) and photos again are strong.
I would focus hugely on this. We were together a long time before we got married (despite being nagged at constantly..!) so in our photos you see us getting older, greyer and fatter!! No one can argue with that!!!