Hello, Charity and welcome to planDisney. I'm glad you dropped by with this question. Needing to reschedule a Walt Disney World vacation isn't often a pixie-dusted activity, so hopefully, I can help make the process a bit easier on your family member.
Now, Charity, your family member has two choices with already purchased tickets. First, they could allow the tickets to lapse and select dates later when they know when they'll be able to visit. This method could include a bit of fact-finding as sometimes tickets that have expired aren't shown on your My Disney Experience account, meaning you'll need to
"recover" the unused tickets by reaching out to a Cast Member about ticket usage before new dates can be selected. If your family member chooses this option, I would encourage them to keep all email receipts showing the date of purchase to verify tickets later.
Another choice is to
select dates in the future, understanding that you might need to change those dates for a third time, eventually. In this situation, your family member would log into their My Disney Experience account and view tickets by clicking on "My Plans." From there you'll see prompts that allow your family member to change dates.
Please keep in mind, Charity, that as theme park tickets are
priced based on dates of usage, it's possible that your family member will need to pay the difference should there be one.
No matter what season, day, or date, I know that when your family member finally visits the Most Magical Place on Earth, it will be an unforgettable vacation. If you have additional questions, please come on back to planDisney!
Lauren