noun
daughter and heiress; daughter who inherits the family estate
Refers to a daughter who is the designated successor to the family, business, or property, often in a traditional context where a male heir is expected.
彼女は老舗旅館の跡取り娘だ。
She is the daughter and heiress of a long-established inn.
跡取り娘として、小さい頃から家業を手伝ってきた。
As the daughter who will inherit the family business, she has been helping with it since she was little.
一人娘 means 'only daughter' and does not necessarily imply inheritance; 跡取り娘 emphasizes the role of heiress.
Compound of 跡取り (heir, successor) and 娘 (daughter). The exact historical derivation is uncertain, but the word transparently combines these elements.