Earlier quoted context omitted.
Has it?
Yeah, it has, apparently: https://adaa.org/learn-from-us/from-the-experts/blog-posts/c... The idea of a fully private social media profile actually scares my half-sister, since it would mean less likes on her posts, so her friends would get more. We had a conversation about this and the way she reacted wasn't pretty.
Not commenting on the motivations of your half-sister, but the very concept of a "fully private social media profile" makes zero sense, since social media is what you engage in to share stuff with lots of people. Compare with "fully private blog".