Aloha, Roy!
Welcome to planDisney, and thank you so much for surfing by with your question. Roy, see the line where the sky meets the sea? It calls me, and it sounds like it is calling you too! Because there's no place I'd rather be than riding the Hawaiian roller coaster ride at
Aulani! Roy, I would recommend calling Guest Services at Aulani at (844) 284-7644 to see if you can add your Guest to your luau reservation. On our last visit to Aulani, there were no tickets available online; however, when I called, they were able to find additional seating and that is how we were able to get Preferred Seating to the
KA WA'A Luau. I would explain that she was just added to your Resort reservation, and that you would like her to be able to join you for the luau. If they still have her waitlisted, you can call every day to see if anything has changed and she can be confirmed, and you can even check again the day of the event. Guests' plans change regularly, so I would imagine there is always a chance that she would be able to be seated with you in the Preferred section. In my experience at all Disney Resorts and experiences, checking often has been the best way to be successful in securing desired reservations. It isn't a guarantee, but it gives you the best chance of grabbing available reservations when they are released.
I hope this helps you, Roy! If you have any further Disney vacation planning questions, surf back here to see me and I'll be so happy to help you. Afterall, you are part of our 'ohana. 'Ohana means family, and that means nobody gets left behind.
A Hui Hou (it means "until we meet again" in Hawaiian),
Keri