Board Thread:Theories and Speculation/@comment-25319479-20160816140121/@comment-26369387-20160816164055

TheCorpseBride10 wrote: I think he probably told her. And Sakura. Considering she knows about the forehead poke. But he also probably told them how he didn't want anyone else to know, because he doesn't want anyone else's name to be ruined. And they probably decided to respect his wishes. I'm almost certain he told Sakura, but still 50/50 on Sarada.

Not necessarily. In chapter 699, Sasuke poked Sakura on her forehead, so she could have taken the forehead poke from there, without knowing about its connection to Itachi. There is possibility that Sasuke told her truth about Itachi and the Uchiha while they were travelling before Sarada's birth, though, so it's 50/50 with Sakura.