Thirties and beyond: four women with nothing to prove and every reason to enjoy the evening

Margo, 166 cm with lacquer-dark hair, has the calm of a torch singer waiting for her cue, composed, dressed in velvet and happy to stay a little mysterious, with a serious love of sculpture and Satie at the piano. Nancy, 170 cm, has the sunny kind, golden blonde, a daily swimmer and a born road tripper who draws everyone at a table into the same conversation. Sonya has calm by practice, a dancer's posture and a morning meditation habit, and she can take the heat out of a frantic day in a few quiet sentences. Violetta is calm on the surface, tall and unreadable at 178 cm, until the deadpan jokes begin.

A room full of strangers is where this chapter shines. At a launch on Bond Street, a charity dinner in the Great Room at Grosvenor House or a client table where the conversation genuinely matters, each of the four can hold her own with anyone, remember every name and leave an impression that reflects well on you. The society pages were written with evenings like these in mind, and three of the four feature there.

Their style is as settled as their manner. Margo favours vintage velvet and a cocktail ring on an unexpected finger, Nancy gold jewellery and a linen shirt dress by day, Sonya midnight crepe with a single strand of pearls, Violetta liquid gold or a cream silk suit. None of them needs a dress code explained twice.

Plenty of agencies file women over thirty under one tired label. We do not, partly because it is lazy and partly because it is simply wrong: the four here are at the height of their confidence, with passions, opinions and a sense of style fully formed. What this chapter describes is a manner, assured and unhurried, rather than a category to be searched for.

Nancy is also one of the blondes and a curvaceous cover. Margo and Violetta appear in slim and slender, Violetta among the statuesque, and Sonya in both petite and toned and athletic. For the chapter before this one, turn back to the late twenties.

The first hour is £400, the same as in every chapter, and longer formats, from a four hour dinner at £1,300 to an overnight at £2,400, are on the rates page. For a weekend, Bella agrees one figure with you before anything is confirmed, and whatever the format, the companion herself receives the fee in person on the day.