How to Be a Heroine by Samantha Ellis: “Travers’s unflappable, imperious magical nanny Mary Poppins (first in print in 1934), and Lady Slane, the heroine of Vita Sackville-West’s 1931 novel All Passion Spent, who is ecstatic to finally be single, when she is widowed at 88 after years of blameless duty as a diplomatic wife.”