Hillary Clinton isn’t the only woman struggling to find an ideal mix of feminism and femininity, one that allows a woman to behave both like and unlike a man without being penalized either way. Mothers of daughters, even if they don’t support the former first lady, feel, if not her pain, at least her conflict. You need only look at the staggering success, in a publishing industry gone soft, of two advice manuals for young women, “The Daring Book for Girls” and “The Girls’ Book: How to Be the Best at Everything.” Those volumes were inspired by “The Dangerous Book...