When this incident first happened (on the day of the bomb scare), it was alleged that AM's sister handed the book to DH's paralegal. She's typically seen in court seated directly behind DH. There would be no crime here until the contraband was proven intended for the defendant, AM. IMO, the paralegal could have refused the book on the spot or given it to the bailiff-- citing she received the book unaware it was intended for the defendant.
IMO, it's just part of the Murdaugh mentality that they are above following the rules applicable to all defendants at trial. Books are not illegal but there's a protocol to follow that includes going through the jail system.
To my knowledge, little more was made known except the following day, both Buster's and AM's sister's seats in the gallery were bumped backward a few rows. At the time, it was reported that Buster and AM's "I love you" exchanges as each was being evacuated from the courthouse were audible -- another courtroom violation of communicating with the defendant. MOO