kinship traced through the mother's family is called what kind of descent
Matrilineality Matrilineality is the tracing of descent through the female line. It may also correlate with a societal system in which each person is identified with their matriline – their mother's lineage – and which can involve the inheritance of property and/or titles. A matriline is a line of descent from a female ancestor to a descendant (of either sex) in which the individuals in all intervening generations are mothers – in other words, a "mother line". In a matrilineal descent system, an individual is considered to belong to the same descent group as her or his mother. This matrilineal descent pattern is in contrast to the more common pattern of patrilineal descent from which a family name is usually derived. The matriline of historical nobility was also called her or his enatic or uterine ancestry, corresponding to the patrilineal or "agnatic" ancestry.
Sibling Half-siblings are people who share one parent but not both. They may share the same mother but different fathers (in which case they are known as uterine siblings or maternal half-brothers/half-sisters), or they may have the same father but different mothers (in which case, they are known as agnate siblings or paternal half-brothers/half-sisters. In law, the term consanguine is used in place of agnate). They share only one parent instead of two as full siblings do and are on average 25% related.[3]