Since it sounds like your booking is made in US$ (hence the need for FX), this is from the
DCl website:
DEPOSIT/PAYMENT INFORMATION
A deposit is required to confirm a reservation. Deposit amount will be determined at time of booking. Vacation and cruise packages are subject to cancellation if full deposit is not received in our office within the option period specified at time of booking. For reservations confirmed in U.S. dollars, final payment in the form of a check or credit card (Visa®, MasterCard®, American Express®, Discover® Card, Diners Club®, Japanese Credit Bureau or Disney Reward® Visa® Credit Card) must be received on the date determined at the time of booking. For reservations not confirmed in U.S. Dollars, acceptable forms of payment are Visa® and MasterCard®. Payment policy for group travel may vary. Please contact your
Travel Agent for complete details. Failure to strictly comply with the deposit and final payment schedules, or any other applicable policies and procedures, will result in the automatic cancellation of pending reservations and applicable fees will be assessed.
For payments by mail, send to:
Disney Cruise Line
PO Box 277763
Atlanta, GA 30384-7763
For payments by services such as Federal Express®, Airborne®, or UPS®, send to:
Disney Cruise Line
Bank of America Lockbox Services
Lockbox 277763
6000 Feldwood Road
College Park, GA 30349
(407) 566-3500
Source: https://disneycruise.disney.go.com/contracts-terms-safety/terms-conditions/united-states/
I know that I have been able in the past when I need to make a payment in US$ to get a check in US$ through my bank (I paid them, I think it was DEM at that time) here in Germany and they had a bank account in the US, so the check was drawn from my bank's bank in the US. Hope this makes sense. It cost an additional fee. I guess your wife working at a bank will hopefully know what I am taking about. It seems that there is no possibility to pay by direct transfer. Of course you could always ask DCL. I would send them an email though and not do it via phone, so that you have a written answer with the bank account details.