One of the features of Game of Thrones is the number of characters—some quite significant—who are children. Two smaller parts along these lines have now been filled, according to Winter is Coming: Callum Wharry as Prince Tommen Baratheon and Aimee Richardson as his elder sister Princess Myrcella. We reported on her casting for the pilot last year, although it was indicated then that hers was the sort of role that may be recast if the series went forward. Clearly, that’s not the case.