Q. The examples of titles and offices in chapter 8 of CMOS suggest that you would condone these sentences: “The queen had tea with the Queen Mother.” “The president and the First Lady waved to the crowd.” Is that a correct interpretation of Chicago style?

A. Not exactly. Rather, CMOS encourages users to apply its guidelines with flexibility and common sense. When rules bump up against each other, try to think like an editor. “First Lady” is conventionally capped as an honorific because its meaning isn’t always clear if it’s lowercased: In line at the theater, the first lady was wearing no coat. (Who was coatless, the president’s wife or the woman standing first in line?) In your sentence, paired with “the president,” “first lady” may be safely lowercased, since confusion is unlikely. In your paired examples, treat both titles the same, whichever style you choose.