noun
school for girls from wealthy and famous families
A somewhat dated term evoking an elite finishing-school image; often used in fiction or nostalgic contexts.
彼女はお嬢さん学校で礼儀作法を身につけた。
She learned etiquette at a school for young ladies from wealthy families.
Similar meaning but uses the more honorific お嬢様, giving an even more refined or exaggerated nuance.
Compound of お嬢さん (young lady) + 学校 (school). The exact origin is uncertain, but it likely arose as a colloquial term for exclusive girls' schools.