For true royal decorum, look no further than the re-emergence of Catherine, Princess of Wales.

After months of quietly undergoing chemotherapy, having famously declared a retreat from public duties, the princess announced, just last Friday, that she was feeling well enough to attend the Trooping the Colour ceremonies the following day.

Rather than indulge — as a certain duchess tends — in victimhood, self-pity, oversharing and navel-gazing, the princess expressed gratitude, humility, and a desire to celebrate with her family and the King, himself enduring his own cancer battle.

Alongside a new photo of Kate standing alone in a lush wooded green, looking up towards the sun in a spirit of health, renewal and optimism, a statement read:

‘I have been blown away by all the kind messages of support and encouragement over the last couple of months… as anyone going through chemotherapy will know, there are good days and bad days. On those bad days you feel weak, tired and you have to give in to your body resting… I am learning how to be patient, especially with uncertainty’.

After months of quietly undergoing chemotherapy, having famously declared a retreat from public duties, the princess announced, just last Friday, that she was feeling well enough to attend the Trooping the Colour ceremonies the following day.

Rather than indulge — as a certain duchess tends — in victimhood, self-pity, oversharing and navel-gazing, the princess expressed gratitude, humility, and a desire to celebrate with her family and the King, himself enduring his own cancer battle.

Kate went on to write that ‘I am not out of the woods yet’.

This is a remarkable admission for a woman who is quite obviously a perfectionist, who rarely sets a foot wrong, whose public presentation is ever immaculate, whose three young children are astonishingly well-behaved.

Kate Middleton, for the first time, has shared her fears and vulnerabilities, perhaps even a tendency towards impatience. How human. How honest.

She began not with her own sorrows but with a note of thanks, before commiserating with her fellow travelers.

It was a jolting yet very welcome announcement.

Now, of course, as Kate’s sudden return generated global headlines, the supporters of Montecito’s despoiling duchess seemingly couldn’t allow her ailing sister-in-law the spotlight.

Yes: Meghan Markle, more stubborn than kudzu, popped back up again — or rather, a surrogate did.

Of course, while there’s no way to know if Meghan had any awareness of this latest stunt, it certainly felt woefully predictable.

Hours before Kate’s appearance at Saturday’s parade, Harry’s great pal Nacho Figueras posted a jar of American Riviera Orchard jam — a new flavor, a limited edition (‘2 of 2’ the jar read) — with that basic muslin wrap and cloying hand-tied bow.

Hey — at least this label wasn’t peeling!

Figueras also posted a jar of dog treats, which looked to be labeled with Meghan’s ostentatious calligraphy.

And it’s all led to a rather well-deserved backlash — not just over the timing, but over the content itself.

As Kate’s sudden return generated global headlines, the supporters of Montecito’s despoiling duchess seemingly couldn’t allow her ailing sister-in-law the spotlight.

Hours before Kate’s appearance at Saturday’s parade, Harry’s great pal Nacho Figueras (above, center) posted a jar of American Riviera Orchard jam — a new flavor, a limited edition (‘2 of 2’ the jar read) — with that basic muslin wrap and cloying hand-tied bow.

Hey — at least this label wasn’t peeling! Figueras also posted a jar of dog treats, which looked to be labeled with Meghan’s ostentatious calligraphy.

Meghan, after all, is the same woman who recorded Harry’s marriage proposal on her iPhone and used that footage in their Netflix docu-series.

The same woman who brands herself a feminist yet reminded the world, during that incendiary Oprah sit-down, that Kate’s one-time nickname had been ‘Waity Katie’.

Who, again on Netflix, smirked as she appeared to mockingly reenact her introduction to the late Queen with a deep curtsy.

Nothing Meghan does ever feels accidental. It would hardly be the biggest surprise if she had some hand in the timing of this new promo for the still-merchless ‘ARO’.

And, if so, then how did Meghan, who became the Duchess of Hertz at last year’s Women of Vision awards, lecturing the crowd about the importance of ‘daily acts of service, in kindness, in advocacy, in grace and fairness’, not see that this would be an epic face-plant?

Catherine, Princess of Wales, bravely fulfilling a public duty amid chemotherapy vs. sweetmeats and dog treats on Instagram.

It’s enough to make you wonder: has Meghan lost her touch?

Remember everyone: Be kind!

Remember, too: When Kate was convalescing after surgery in January, followed by the clatter around Photoshop-gate in March, Meghan decided to launch ‘ARO’, posting an old-timey video of herself in the kitchen, then seen from afar in a voluminous black ballgown — for day! — all set to, perversely, Nancy Wilson’s classic ‘I Wish You Love’.

Days later, when Kate announced to the world that she had cancer, Harry and Meghan — so estranged that they learned this news along with the rest of us — wasted no time issuing a press release.

‘We wish health and healing for Kate and the family,’ their statement read, ‘and hope they are able to do so privately and in peace’.

HA! Meghan and the word ‘peace’ seem at great odds, do they not?

Alongside a new photo of Kate (above) standing alone in a lush wooded green, looking up towards the sun in a spirit of health, renewal and optimism, a statement read: ‘I have been blown away by all the kind messages of support and encouragement over the last couple of months…’

It strikes me that if they wanted to give their full support, they would finally set aside their grievances, drop the pernicious victimhood act, and apologize for insinuating to Oprah that the royals were racist.

Apologize, too, for Harry reprinting private texts between Meghan and Kate in his memoir, or for the major mistake of mouthpiece Omid Scobie naming Kate and Charles — now the most sympathetic and admired royals going — as those so-called ‘racists’, information that has still not been denied by the Gruesome Twosome.

Then again, Meghan is the woman who, amid a backdrop of impoverished African children, complained about her mental wellbeing and griped that ‘Not many people have asked if I’m okay’.

Kate, meanwhile, spent hours on her feet on Saturday, in heels and a form fitting white dress, to show up for her sick father-in-law and for her country, no doubt at great personal toll. The princess, understandably, will most likely have been left drained and fatigued — but she is not asking for our pity.

Compare Kate’s most recent statement with Meghan’s typical logorrhea, her vintage L.A. word salad of self-validation and narcissism, signifying nothing.

Here she was in Nigeria just last month, cosplaying as if on official royal business, explaining how her Nigerian ancestry only made her that much more awesome.

‘What has been echoed so much in the past day is, “Oh, we are so not surprised when we found out you are Nigerian.” It is a compliment to you, because what they define as a Nigerian woman is brave, resilient, courageous and beautiful,’ she said.

And Meghan wonders why, with each successive attempt to rival Kate, she only ever fails.