Use this domain for words related to siblings.
Louw Nida Codes:
10C Kinship Relations of the Same Generation
What words refer to the children of your father and mother?
sibling, brother, sister
What words indicate the order in which your brothers and sisters were born?
elder brother, elder sister, younger brother, younger sister
What words refer to the children of your father by another mother, or of your mother by another father?
When your father or mother marries a person who already has children by a previous marriage, what words refer to those children?