In “Romeo and Juliet,” the star-crossed heroine asks: “What’s in a name? That which we call a rose, by any other name would smell as sweet.” People far less infatuated have wrestled with this concept for hundreds of years: How much should a name signify, and does it actually affect what or who a person is? Meghan, Duchess of Sussex, would like a word. In her new Netflix series, “With Love, Meghan,” the duchess, who is married to Prince Harry, told the actress Mindy Kaling that her last name was Sussex, correcting Ms. Kaling, who had referred to her by a more familiar name: Meghan Markle. “It’s so funny, too, that you keep saying Meghan Markle,” Meghan said in the second episode of the series, which premiered last week. “You know I’m Sussex now.”