Families are complicated. Even in the US, we struggle to accurately define family from a social and legal perspective. Here, it is even larger. Let me try to define terminology.
Mama is the woman who gave birth to you.
Other Mamas, or small/big mamas, are your mama’s sisters.
Papa is the man who is married to your mama.
Other papas, or small/big papas, are your papa’s brothers.
Aunties are your papa’s sisters.
Uncles are your mama’s brothers or sometimes a man’s nieces by his sisters.
Brother or straight brother is the boy who came from the same womb as you.
Sister or straight sister is the girl who came from the same womb as you.
Cousin-brother or sister is the child of your papas brothers or your mamas sisters.
Cousin brother or sister can be the child of any of your parents siblings, depending on other factors.
Child or straight child is the one you contributed DNA to.
Child is also the child of your brothers and sisters or your spouses brothers and sisters.
Bubu is the person two generations away in either direction, either grandparent or grandchild and extends out to cousins and then some.
Adoptions are common and are treated as if they were born into the family but when trying to distinguish between born and adopted people will say the mama who birthed you vs your straight mama.