The taxi pulled up outside the front entrance to Harrods. A braided doorman leaped forward to open the door, as if knowing instinctively that Mummy was inside.

“Hello, Albert,” she said, turning the full force of her radiance on to him. “How are you today?”

“All the better for seeing you, Your Grace,” he said as his fingers closed around the generous tip.

“How sweet of you to remember me,” she said. As if he wouldn’t.

Then she swept through the cosmetics department, pausing only long enough to request a jar of her favorite face cream to be ready for her on her way out; the glove department, pausing only long enough to ask for emerald green kid gloves and a matching scarf and then she was in the lift going up to the dress department. During the next half hour, she must have tried on at least twenty and discarded them all as too frumpy and too last-season.

So we were off again, at whirlwind speed, collecting gloves, scarf and face cream, and commissioning someone to run to the food hall and have smoked salmon delivered by noon to the house. As usual, I was in awe of her energy, efficiency and the way she took it for granted that every employee of Harrods was there only for her. If only I could have been a little more like her, in temperament and in looks. I sighed. She was petite with huge, blue eyes, giving a quite false air of being helpless and delicate. I was tall and angular with the healthy, outdoorsy appearance of my hardy Scottish ancestors.

“Where to now, do you think?” she asked as another taxicab screeched to a halt beside us. “Not Barker’s. Too depressing. Selfridge’s? Too common. Liberty’s? Too country. Fenwick’s? Now, there’s a thought. She tapped on the glass. “Bond Street, driver. One should find something there.”

And so we set off again. “Have I time to get my hair set, do you think?” she asked. “That adorable young man around the corner from the Burlington Arcade will fit me in, I know. You can wander for a while, darling, can’t you, while I have a teeny little shampoo and set?”

Privately, I thought that one of the more depressing things in the world was to wander along Bond Street with no means of buying anything in the shops, but it was only a rhetorical question and a fine enough day for walking. We dashed through Fenwick’s, acquiring a Fair Isle skiing jumper, just in case she went skiing, a bathing wrap in case she decided to bathe and a pair of good, sensible, tweed trousers for tramping around the Alps. To this she added a variety of undergarments.

“Of course only the French know anything about underwear,” she said in her clear, theatrical voice, which carried to the gods. “The English don’t seem to think undies should have anything to do with seduction or sex. What red-blooded man would possibly want to tear off these voluminous English knickers?” And she brandished a particularly large pair. Several ladies up from the country turned around in horror. One fanned herself with her gloves. “But there are times when one would rather be warm, and there’s nothing like good English wool for that.”