FOR simplicity’s sake, let’s call me a childless spinster. So when my younger brother and his wife announced their first pregnancy, I — then in my mid-30s — listened hopefully for that famous tick-tock, and when it didn’t sound, slunk back to my familiar unknown. My indecision, I was forced to accept, was fast reaching its expiration date. And then on a bright March afternoon I entered a hushed delivery room, and my brother handed me a small white bundle, and I felt something, not maternal exactly, but decidedly formidable: a primal pull, a plummet. It was my niece, Sophie, 2 hours old.

That was three and a half years ago. Ever since, I’ve been going around telling people that Sophie is my most passionate relationship. I play it as a rueful quip about the state of my romantic life, but in truth I’m deadly serious. When I’m low, I scroll through the latest batch of digital photos sent by her mother and sit back as my brain floods with endorphins. A real-life visit, when Sophie leaps into my arms, presses her tiny cheek against mine and won’t let go, is an endorphin tsunami. Later, when she starts shrieking in tongues and throwing handfuls of pennies across the room, her parents whisk her off to bed and I settle down with a novel.

In June, the Pew Research Center reported that nearly 1 in 5 American women in her early 40s has never had a child — compared with 1 in 10 in the 1970s. I suspect the Census Bureau doesn’t have a line tallying the current aunt population. But it stands to reason that as women marry and have children later, if at all, they have more time to enjoy being an aunt. How many of these single, childless women wonder, as I have, if being an aunt beats being a mother?

Certainly the aunt’s public image is far more appealing than that of the modern “mommy,” that bedraggled, desexualized creature forced to spend her disposable income on mammoth strollers or careen about in “I Don’t Know How She Does It” fashion. Who is popular culture’s most popular aunt, the glamorously madcap Auntie Mame, if not Holly Golightly with crow’s feet? (Both heroines, as it happens, emerged nearly simultaneously in the late 1950s, each with a long and slender quellazaire between her fingers.) There are many less glamorous aunts, of course — Aunt Jemima, Auntie Em, Spider-Man’s Aunt May. But the eccentric and single socialite Mame Dennis, with her colorful wardrobe and ever-changing décors, best encapsulates the aura of self-sufficiency we like to assign to the role. The aunt exists outside the immediate family unit, ambassador to a universe of other options, as well as — crucially — a grown-up who isn’t an authority figure or disciplinarian.