During Spring Festival my sister-in-law went back to her parents' home.
Tips
usage
Specifically the wife of your 弟弟. Chinese sister-in-law terms are split by marriage direction: 弟媳 (younger brother's wife), 嫂子 (elder brother's wife), 妻妹/小姨子 (wife's younger sister), etc. English 'sister-in-law' collapses all of these.
