There’s been a clutch of middle-aged danseuses taking leave of life in one way or another recently. We’ve seen the abject (Mariinsky star Diana Vishneva’s solo show at the Coliseum) and the magnetic (Alessandra Ferri mournfully channelling Virginia Woolf at the Royal Ballet). A fortnight ago, the Paris Opéra’s aristocratic Aurélie Dupont retired from the stage in one of her great roles, as did American Ballet Theatre’s stellar women Paloma Herrera and Xiomara Reyes in New York.