Greetings to you, Jade!
Welcome to the Disney Parks Moms Panel. I'm so glad that you stopped by with a question for us. It sounds like you are ready to book your magical
Walt Disney World Resort vacation, and I know you must be excited. There's definitely no better place to make memories that will last a lifetime!
If you need to make changes to your reservation, you can do so up to 30 days prior to your arrival with no penalty and no need to cancel and rebook your package. So in the case that your family member is unable to join you, that person could be removed from the reservation without any penalty. However if you make a change to the reservation less than 30 days from your arrival, you could be subject to a change fee. It is my understanding that you will not have to cancel and rebook your package either way though, so you won't lose your preferred room or any special offer you received. Hopefully you will know prior to that timeframe whether or not he or she will be able to join you.
I hope this helps to answer your question. If you need more assistance on changes to your reservation, then just
call the reservation line and a friendly Cast Member can walk you through it. And don't hesitate to let us know if we can do anything else for you. Have a magical day!
~Carrie