Ahoy, Rebecca - welcome to
planDisney!
Disney Cruise Line staterooms are priced based on double occupancy, as you mention, and this is something that is somewhat standard within the cruise industry. While it might seem like simple math to add an additional person to your stateroom, there are some other factors that come into play.
For example, just because there is room in
your stateroom for an additional person, doesn't necessarily mean there is room on the
ship for that additional person. You see, Rebecca, there are many different stateroom types with different capacities. So, if your cruise is predominantly filled with couples staying in staterooms that can accommodate four or five people, the ship is unlikely to be full. However, if most of those staterooms are instead filled with families or groups of four or five people, that's a different story. Disney Cruise Line wants to ensure that everyone can enjoy their experience, and for that reason, the number of passengers is carefully monitored.
So, to get back to your question, it
is possible to add an additional person to your stateroom at a later date, but it is not guaranteed. This is something that you can enquire about by
calling and speaking to a Disney Cruise Line Cast Member for assistance. They will be able to look at your reservation and let you know what options you have!
I hope someone is able to join you, and that they are able to be accommodated - Disney Cruise Line sailings are always more fun with a pal or two!
Ryan J.