This is what I thought when I first met her: “She is a strong woman, not ego-driven but protective of kith and kin. Those merry eyes, the warmth, the ability to get the help cracking in a jolly way and then not so jolly. A lack of pretension, a breeziness, but underneath she is Greenwich granite, one of the women who settled the hard gray shores of the East and summoned roses from the rocks.”

That’s how I saw Barbara Bush 30 years ago and wrote in a book, and though I wouldn’t put it in quite those words today—Greenwich, Conn....