My brother is in the twin bed next to mine, and my sister and mother are sharing the king-sized bed off our tiny living room. We're all within whispering and giggling distance of each other in a whitewashed bungalow with peaked ceilings at the Isle de France resort on St. Bart's. No, this isn't my Remembrance of ?Vacations Past—it's a scene from a recent just-the-four-of-us getaway that my two siblings and I took with our mother, Estelle.

It all came about last fall, when Jody, Rob, and I realized that out-of-sync school vacations and other roadblocks were going to thwart a big family gathering yet again. Reunions don't require everyone, Jody pointed out. Maybe we should leave our families at home?Miraculously, our spouses all agreed to look after the kids while we took off. Our always game mother was so delighted, she offered to help pay the way.

The last time it had been just us was 19 years ago, when our father was fatally ill and we were all commuting home to Boston. Despite the unspeakable sadness of those days, being back together had been a rare and wonderful thing. Since then, our far-flung clan had mushroomed. What would it be like, I wondered, to leave my husband and kids for a week and return to being the baby of the family?

I arrived on St. Bart's hours ahead of the group, took a look at our intimate, if extraordinarily stylish, setup, and freaked out. This was meant to be a get-together, not a honeymoon. And what about our location, across from an exquisite beach but also right off the parking lot? Everyone else arrived equally unhinged: our mother had grabbed the wrong passport—one that expired in 1998—and had to plead her way onto two flights. Rob immediately shuttled Mom off to the bar for a calm-down vodka and tonic, only to have the 14-euro ($18) cost send her further into a tailspin. It looked as if we were going to have to survive on Rob's travel stash of dehydrated peas. But that night we splurged on perfect French salads and grilled fish at the hotel's restaurant—and from then on we loved everything. Even our parking lot was charming, with its two-toned Smart cars that looked like saddle shoes on wheels. In the days that followed, we met up with local friends at hidden beaches, applauded as Mom demonstrated yoga poses in the sand, raced each other for the front seat of our rental car, were instructed by our mother to work on yawning less audibly, and told each other things like, "That wrinkle is so ugly, you should consider Botox." In other words, we discovered that while you may not be able to go home again, you can always go on vacation. — MARGOT GURALNICK