Translation guide
In Japanese, referring to one's own eldest daughter versus someone else's requires different vocabulary. The most common and neutral term for 'eldest daughter' in a family is 長女, but in conversation, people often use descriptive phrases or names.
When talking about your own eldest daughter within your family or to others.
Neutral term for 'eldest daughter'. Used in formal contexts or when filling out forms. In casual conversation, it can sound a bit stiff.
私の長女は大学生です。
My eldest daughter is a college student.
Literally 'the older/upper daughter'. Common in casual conversation when you have multiple daughters.
上の娘が来年結婚します。
My older daughter is getting married next year.
Literally 'the topmost daughter'. Used when you have three or more daughters to specify the eldest.
一番上の娘は医者です。
My eldest daughter is a doctor.
When talking about the eldest daughter of another family, using polite language.
Also used for other people's eldest daughters, especially in formal or neutral contexts. Can be combined with honorifics.
田中さんの長女はピアノが上手ですね。
Mr. Tanaka's eldest daughter is good at piano, isn't she?
Polite word for 'daughter'. When context makes it clear you mean the eldest, you can use this. Often combined with 上 or 一番上.
Polite version of 上の娘, using 娘さん instead of 娘.
上の娘さんはもう社会人ですか。
Is your older daughter already working?
When filling out documents, family registers, or in literary descriptions.
In Japanese conversation, it's very common to refer to family members by their given name plus a kinship term or just by name, especially when the listener knows the family. For example, if the eldest daughter's name is Yuki, you might say ゆき姉 (ゆきねえ) within the family, or simply ゆき when talking to someone familiar.
長女 is the standard dictionary term and is used in formal writing and speech. 上の娘 is more colloquial and natural in everyday conversation when you have multiple daughters. If you only have one daughter, you would just say 娘 (むすめ).
お宅の一番上のお嬢さんはおいくつですか。
How old is your eldest daughter?