Philly Girl, you can move your reservation to another agent, but your current agent might charge a fee for the change.
Can't remember when you are cruising, but if there's time, maybe you could get one passport a month and have them all before you sail?
Carnival Elation March 11
Carnival Imagination Sept 07
Carniival Sensation Dec 06
RCI Sovereign of the Seas Sept 06
Carnival Miracle Sept 05
Carnival Glory Sept 04
Carnival Fantasy Jan 04