Ok from what I understand T'Challa was T'Chaka's son with his ex-wife N'Yami who died in childbirth but he was raised by his step-mother Ramonda. Ramonda and T'Chaka are the parents of T'Challa's half-sister Shuri right? T'Chaka also has another son with a wife who was from another tribe and this son was Jakarra who became a villain.

So was Jakarra's mother T'Chaka's first wife or second wife? (I'm assuming Ramonda is the 3rd)

If Jakarra is the eldest son then why wasn't he the Black Panther? If Jakarra's mother was the second wife then she was T'Challa's step-mother before Ramonda. Did Ramonda help raise Jakarra as well as T'Challa and Shuri or was he always away at foreign schools?