It's a gossipy and thinly source report given a dose of credibility by its source: the Times of London. The paper reports that Meghan Markle's sister Samantha has been placed on a "fixated persons list" due to the potential "reputational risk" she poses to the royals. The Times uses language like "understood to" and "believed to" to describe the situation, which neither Kensington Palace nor Scotland Yard commented on. Still, the paper alleges the Duchess of Sussex's personal protection officers have conferred with Scotland Yard’s Fixated Threat Assessment Centre (FTAC) "about the embarrassment that Samantha could cause if she attempts another public rapprochement."
That's an apparent reference to Samantha Markle's unannounced October stop by the palace and the Christmas card she sent pleading for family reconciliation, which Fox News reports was highly publicized and subsequently rescinded, with Samantha saying her sister didn't "deserve" her Merry Christmas greetings. Samantha responded to the report on Twitter: "This is ridiculous as I'm in an electric wheelchair and I live on a different continent LOL and advocating for doing the right thing by our dad is hardly fixation. Stop your lying nonsense or be sued." (Samantha previously accused her sister of an "unconscionable" lie.)