Daughter refers to human female offspring, whether they are still young, or quite old. Since the term essentially means every girl and woman in existence, it usually only comes up when one of the parents is also being mentioned.
It is also a term sometimes used in a metaphoric sense in other fields. For instance, the main circuit board in a personal computer is called a "motherboard", and the smaller cards that plug into to to add functions are sometimes called "daughterboards".
There is an organization called the "Daughters of the American Revolution", whose members are women who can trace their ancestry to people who lived in what became the United States during the revolutionary era.