Since you are requested to send the passport within 60 days, you have to send it along with the letter. Don't waste this chance and the time frame.
I know someone had already advised you on this before, and you are the best person to judge your situation, nonetheless, try to reconcile with your spouse. Convince her that this is a one life chance that might never come again. It's her future and the future of her successors.
Thought to share these few words.
Send your passport with the letter and I wish you sincerely all success.
Cheers
Mezo