(Someone else's) daughter — a polite form of address referring to another person's daughter (less formal than お嬢様).
社長のお嬢さんは今どこにいらっしゃいますか？
Where is the president's daughter now?
隣の家のお嬢さんはピアノが上手だ。
The neighbor's daughter is good at piano.
お嬢さん、お荷物お持ちしましょうか？
Miss, shall I carry your luggage for you?
Young lady — a somewhat polite way to refer to a young woman; often used by older speakers but can sometimes sound overly familiar depending on context.
お嬢さん、じっとしていなさい。危ないから。
Young lady, stay still. It's dangerous.
お嬢さんたち、集合時間は何時ですか？
Young ladies, what time is the meeting?