Where does “兄弟姉妹” come from?

兄弟姉妹 (Japanese) comes from Japanese 兄弟, from Japanese 兄, from Old Japanese あに, from Japanese の, from Old Japanese の, from Middle Chinese 能 — talent, ability.

兄弟姉妹 (Japanese): siblings

Definitions

siblings

Ancestry of “兄弟姉妹”, step by step

兄弟姉妹 traces back through two separate lines of ancestry.

via Japanese 兄弟

Step	Language	Word	Meaning
1	Japanese	兄弟	brothers; siblings; brothers and sisters;...
2	Japanese	兄	elder brother; elder brother-in-law; Short for...
3	Old Japanese	あに	—
4	Japanese	の	genitive case marker; nominative case marker in a...
5	Old Japanese	の	plain, field
6	Middle Chinese	能	talent, ability

via Japanese 姉妹

Step	Language	Word	Meaning
1	Japanese	姉妹	sisters; the status of being a sister; Rare...
2	Japanese	妹	a close female companion; one's own younger...
3	Japanese	人	a person, human; an individual; mankind, people
4	Proto-Japonic	*pitə	one

Every word from Middle Chinese 能 →Every word from Old Japanese の →Every word from Japanese の →