I can't recall ever learning anything about N'Yami while T'Chaka gets a lot of attention.
How did she die?
Did T'Chaka cheat on her when he fathered T'Challa's half-brother Jakarra? Or did he divorce N'Yami and marry Jakarra's mother before he divorced her and married Ramonda and fathered Shuri? Or did T'Chaka have a polygamous multiple wives situation?
T'Chaka has numerous relatives...do we know any of N'Yami's extended family?
I have no idea about Jakarra and his mother...had to do some research.
It is my understanding that N'Yami died in childbirth with T'Challa. Ramona is the only mother T'challa has ever known. I think T'Chaka only had the two wives. Now concubines or something else....no idea.