On Sunday, as hundreds of thousands queued to see the mortal remains of our Queen lying in state, I stood in a shorter queue, to see a different queen in the flesh. The occasion was my daughter’s long-planned birthday excursion to the West End musical staging of Frozen. And it was magnificent. We thrilled, wept, and whooped all the way through; the show’s high point — the Sparkly Elsa Dress Reveal — even received a standing ovation.