Ahoy, Tammy!
Thanks for stopping by the Disney Parks Moms Panel with your question.
On every Disney Cruise Line sailing, Guests are required to participate in an organized assembly drill before setting sail, in order to comply with U.S. Coast Guard regulations. Guests will be notified by onboard announcements when the drill is to begin, and all guests are required to take part.
That being said, Disney Cruise Line does an amazing job accommodating guests with special needs or who may need alternate arrangements for certain situations. I encourage you to contact
Disney Cruise Line's Special Services Team, and discuss your daughter's particular needs regarding the Muster Drill. The team can be reached by calling (407)566-3602, or emailing them at SpecialServices@disneycruise.com. They are very kind and understanding, and will be happy to talk to you about what options are available to help your daughter have the best experience possible on your Disney Cruise Line vacation.
I hope this is helpful in your planning, and that you and your family have a wonderful time sailing with Captain Mickey and his crew! - Diane W.