Announced with a flourish on Instagram, after a you-can’t-miss-it ‘private’ tea at Claridge’s, Meghan’s collaboration with Nobel Peace Prize-winner Malala Yousafzai was certainly high profile.

Six weeks after a return to the UK, ostensibly to let children Archie, seven, and Lilibet, five, attend a British school, the Duchess of Sussex re-entered public life with a bang.

She said that following the meeting last Wednesday she would be donating a day’s proceeds of all jam and tea sales from her Californian brand As Ever to Yousafzai’s charity, the Malala Fund, in honour of the International Day of the Girl on October 11.

Then on Sunday, alongside a shot of her grinning at that tea, as Malala looked solemn, she shared a joint statement from the pair. ‘When we support the girls today, we empower the women of tomorrow. Access to education is the key to unlocking this.’

She then told her 4.9million followers: ‘This International Day of the Girl, in partnership with Archewell Philanthropies, 100 per cent of net proceeds from As Ever jams and teas will support Malala Fund and its vital work to ensure every girl has access to free safe quality education. Tea for Two has never felt so good. Shop at asever.com’.

It’s not clear what the response was to this rather self-important call to action; her office this week declined to confirm any sales figures from Sunday.

But the big gesture still begs the question as to what a donation of ‘100 per cent of proceeds’ from her brand’s jam and tea sales might in fact amount to.

The answer seems to be a truly modest amount. Even a generous extrapolation from the only available data suggests a day of proceeds from tea and jam will add around £1,900 to the Malala Fund coffers. That wouldn’t even cover those arrestingly wide, white Ralph Lauren trousers Meghan wore to the Mayfair hotel.

A source close to Meghan wasn’t able to deny the final amount could be that low, but repeated that figures could only be ‘speculative’ as her firm does not share such data.

They pointed out that – aside from any money given by Meghan – the gesture should in itself lead to others donating, so would be beneficial twice over. The impact of her support is, they said, in itself a gift.

The problem is that there is arguably a gap between the grandness of the gesture and the attention that greeted it – and its actual real-world impact.

Think of her long-forgotten ‘40 at 40’ initiative, or one-off visits to women’s refuges, or perhaps her crowing on Instagram about sending merchandise from Billie Eilish to a girl who lost everything in the LA fires last year. Who benefits most from these isolated small acts of charity? A cynic might argue it’s Meghan herself.

One thing which can be said with some confidence is that even on this micro scale, Meghan was being relatively generous: her jams and teas are by some margin the best-sellers in her brand.

What we know about As Ever arises from a website glitch in January. At that point, it was possible briefly to determine how much unsold stock there was as customers could order as many jars of, say, raspberry spread as existed. That was widely reported. What wasn’t, was that it was 24 hours before the glitch was fixed – meaning we can say how many candles, sprinkles, jams and wines were sold between January 4 and 5.

Any luxury retailer will tell you these are terrible days for a brand, post-Christmas. Indeed, on that day in January she sold zero bottles of Napa Valley Brut at $89, not a solitary spiced cider kit and not a single $64 candle No519.

The best-seller – shifting 25 units – was the Signature Fruit Spread Gift Box priced at an outrageous $42 for three jam jars. The next strongest seller was the herbal lemon and ginger tea and herbal hibiscus tea, both of which sold ten units in a day, at a price of $14 plus shipping apiece. The orange marmalade sold only two jars, the sage honey five. Figures for some jams and marmalades are missing. But if we assume the trio of raspberry jams sold the same number as the trio of fruit spreads, and that the strawberry spread in a keepsake box sold as many as the lone strawberry spread, then jams and spreads made $4,677 in a day, with $364 worth of tea sold.

How much would that bring in net? Commercial jam generally makes a small margin of 5-10 per cent. Artisan jam generally makes more like 30 per cent, and fancy tea 20 per cent.

If we were to be very generous and assume a really outstanding margin of 50 per cent on both, that would still amount to proceeds of $2,520 (£1,902) in a day.

Meghan’s trousers worn for tea with Malala cost $2,247 (£1,696) and her cashmere sweater $832 (£628) – a total of £2,324.

Beyond what she may have donated, sales on that January day of booze and candles look slow. She sold seven of candle No 084 in 24 hours, each for $64, nine tins of flower sprinkles at $15 and only seven bottles of the 2024 Marlborough Sauvignon Blanc at $35, and seven bottles of Napa valley rosé at the same price.

Wine could be a big money-spinner for As Ever, as on a direct-to-consumer basis she could be making a huge margin of up to $20 a bottle. You have to assume that in the run-up to Christmas, she will make more than that.

In recent weeks she has brought out three different hampers ranging from $211 to $259 and an advent calendar for $148. Her team has now let slip that she will start shipping to the UK at some point. She won’t be selling foodstuffs – due to complications – but tea, candles and bookmarks will apparently go on sale here.

Several sources in California reckon As Ever is a minnow in decline, and some say the UK return is due to Meghan and Prince Harry having burned through the cash from their immediately-post-Megxit deals.

That suggestion is derided by Team Sussex’s paid spokesmen.

So where on earth might Harry and Meghan make money? She is thinking about returning to acting. Her former Hollywood agent Ari Emanuel revealed she is ‘getting booked’ for ‘reality and TV stuff’. Harry can pick up paid speaking events and other work such as his ‘grief masterclass’.

Their best chance is probably if one of their investments in someone else’s bright idea pays off.

But it seems that anyone waiting to get rich from jam, tea and sprinkles may be waiting a very long time indeed.