Welcome aboard, Laura! The Royal Court Royal Tea on the Disney Fantasy is one of the newest events on Disney's ships and has been very popular!
This event is for children ages three and up, so your 13-year old is welcome to attend with you. Tickets are available onboard the ship, as pre-booking is not currently taking place. The cost for one adult and one child is $279. Additional children cost $210 and an additional adult costs $69.
Be sure to check out this
Royal Tea post on the Disney Parks Blog so you get a sense of how wonderful this experience is and you'll read more about all that is included in the cost! The extras that are included for girls include a Cinderella doll, an autograph book, a jewelry box with a charm bracelet and princess charms and a back sack. These items are geared at the younger set, but if those extras sound worth it to your 13-year old, then go ahead and ask about booking this when you get on the Fantasy! Even without the gifts, this is a really unique experience that guests of all ages would enjoy, Laura!
Have fun planning!