After the 1979 one-child policy (独生子女政策), most urban 80s and 90s kids have no actual 兄弟姐妹 — the word took on an aspirational feel. The policy was relaxed in 2016 and fully ended in 2021.
usage
A four-character summary compound: 兄 (older brother) 弟 (younger brother) 姐 (older sister) 妹 (younger sister). Chinese distinguishes sibling order lexically; English collapses to 'sibling.'
