If you didn’t book by yourself tonight - I fully recommend contacting your family’s / your prior trip
Travel Agent. If she has no experience with
Disney Cruise, then either book yourself or try DU.
At this point, cabins shouldn’t be filling up that fast. That usually happens when itineraries are first released (about a year ago) or when they reduce the price on the limited cabins left (where you have no pick of cabins).
(If you want to book yourself and prefer not to do it online, call
DCL to book.)