- Affidavits
- Annotated photos (date, location, event, who is on photo) on paper, 2-3 per page
- Tickets showing you visiting her and vice versa
- Tickets for events you attended
- Marriage certificate
- Docs showing any stuff related to wedding (venue, invitations)
- Emails or messages exchanged between you and her
- Your receipts for the ring you have for proposal or purchase of wedding bands
- Any receipts of gifts or flowers you sent her or her giving you gifts
As soon as you marry you must open joint bank accounts and start co-mingling finances. Even if she doesn't have job, still get the money put into the joint account.
Call utility companies and add her on bills. Add her on your medical insurance.
Get her ID or DL from DMV and have that address match address on your ID, e.g. place where you live.
Adding her on the lease can be done today. Just speak to your landlord. That's one of the biggest evidences of you living together you may have.