Last month, when pressed as to whether she'd be appearing in this year's Celebrity Big Brother, Samantha Markle was coy and then cut-throat.
"Why not?" said Markle, half-sister of Meghan. "Life is about cashing in. You take opportunities as they arise and hopefully you enjoy the ride and make it as positive as you can."
Positive for whom, though? A pay cheque and some celebrity are clearly positive outcomes for Samantha, daughter of Thomas Markle by his first marriage, who went by the name of Grant until her half-sister became betrothed to a prince. It's obvious what's in it for Samantha Markle, author of the allegedly soon to be published memoir In the Shadows of the Duchess, which was originally entitled Diary of Princess Pushy's Sister.
For Meghan, however, as it remains unclear as to whether Samantha will turn up as the final mystery housemate in the Celebrity Big Brother (CBB) house, there's little positive in the prospect.
According to reports, the palace is not too worried about the notion of Samantha Markle appearing on the reality-TV show. This is not just due to the fact that it hardly reflects well on her to line up with Kirstie Alley, the Human Ken Doll, some stars of other reality TV and the no-show Stormy Daniels.
It's also to do with the fact that Meghan has no relationship with her half-sister; they did not grow up together and, it seems, no love has been lost, ever.
The same cannot be said about the situation with Thomas Markle, the shared father of the sisters, who just cannot shut up about Meghan, Harry and his interactions with them.
The new series of CBB launched in the same week that Meghan's father, Thomas, gave yet another interview on the subject of her marriage to Prince Harry.
Last week, Markle gave a TV interview in which he described hanging up on Prince Harry during a heated phone call. According to Thomas Markle, the call followed his exposure for staging paparazzi shots taken before Meghan's wedding to the prince.
In case it's all a blur of bonkers, these photographs of Markle were taken around his home in Mexico, and seemed to show him preparing to depart for the big day in the UK. They were borderline farcical, with one photo showing him in an internet cafe, Googling sights to see in England. Fairly swiftly, Markle was revealed to have been in cahoots with the photographer.
Thomas Markle then reportedly had heart surgery which prevented him from attending the big wedding, and since then, he hasn't stopped talking. Last week, he announced that Meghan had asked him to stop.
"Meghan asked me to tell Samantha to stop talking about her and then asked me to stop talking to Samantha," Thomas said to a UK paper. "I have two daughters. I can't stop talking to one of them. No father should be asked to turn his back on their children. I love Meghan but I also love Samantha."
You could argue that if he loves Meghan, he should stop talking about her. He should have resisted giving that bizarre interview where he warned Prince Harry - should he happen to be watching - never to "raise a hand to Meghan".
Thomas has also observed that Meghan looks uncomfortable and nervous in her new role. Obviously it hasn't occurred to him that the mortification of having her father blabbing all over the place and showing her up might contribute to any discomfort. Nobody wants to be the blow-in who causes issues for their new family by marriage.
And especially not for the family into which Meghan has married. As her sister and father's running commentaries keep an unflattering focus on her that causes embarrassment for a family who prioritise propriety.
They have also historically prioritised the practice of marrying within one's own aristocratic stock, and the relative shame Meghan is drawing on them seems to reinforce that this might be the best idea.
It matters to a newly wed to make a positive impression on the in-laws, and part of that is created by one's own family. It all sounds a bit Pride and Prejudice to talk about good stock, but in the context of Meghan Markle, the lot she has married into haven't really come that far from Jane Austen. They mix and marry among their own sort and who you are, and who and what you come from, really matters.
In the case of Prince Harry and Meghan Markle, the Windsors must wish for the safe ground of marrying into similar stock. The rogue prince really has gone rogue with this particular move and it's not one that they know how to fix.
Last week, it was reported that the palace finally believes it's time to take a more "aggressive" position with Thomas Markle. This follows reports that they were considering getting Queen Elizabeth involved.
In a way, both suggestions are slightly laughable.
What are they going to do? With what can they threaten Markle, beyond estrangement from his daughter, which he has already brought about himself?
And what, they're going to send an nonagenarian great-granny after him? Yes, she's the Queen, but it is clear that this cuts no mustard with Markle.
The rules by which the house of Windsor has operated in the past do not apply in this instance. It's apparent that the Markles do not care about protecting and preserving The Firm. They don't seem to care if they bring shame or pain on Meghan or her in-laws, or for the bigger picture.
As Samantha Markle's attitude to potentially joining CBB suggests, this pair of publicity-seekers are in it for what they can get.
And in Thomas Markle's case, this seems not so much to be about money as about attention.
The danger in the palace approaching Thomas Markle would be that it would only give him more material. Like his less-famous daughter, he seems to be enjoying the ride far too much to stop just yet.