All character pages where the character's first and last name are known have had name titles removed, except this one. The "Miss" obviously is to distinguish mother from daughter, but for me, I just feel that the "Miss" seems out of place since we know her full name and especially since her mother no longer has "Lady" in the title (otherwise I would've been find Lady Sybil Branson and Sybil Branson). I've been told nicknames in titles are no longer allowed, so my solution for this character's page title would be either "Sybil Branson II" or "Sybil Branson Jr."
Does anyone else want to venture an opinion? Just cast a vote.