Hi Brett!
If your nieces are big fans of Anna and Elsa, then they have a few options to see them during your visit. I would agree that Magic Kingdom is definitely a perfect spot for your vacation day. While Anna and Elsa don't have a scheduled Character Experience at Magic Kingdom, your nieces will be able to see them appear in the
Disney Festival of Fantasy Parade. At Magic Kingdom, your nieces would be visit Princess Fairytale Hall, where they can meet
Cinderella and Elena in one area and
Rapunzel and Tiana in a second area.
If your nieces are interested in personally meeting Anna and Elsa, then you should plan on visiting Epcot. The Queen and Princess of Arendelle have graciously opened their summer home so they can
meet Guests at Royal Sommerhus. This is one of my favorite Character Experiences at Walt Disney World Resort because the queue is so beautifully themed to match the details of the movie. While visiting Epcot, be sure to ride
Frozen Ever After to enjoy Arendelle's "Summer Snow Day"!
I think either theme park would make for a
practically perfect Disney day for your family or you could
add the Park Hopper Option to your ticket and enjoy both. T-T-F-N, ta ta for now!
~Crystal