干女儿不是自己亲生的女儿，而是别人把你当作父母，认你做长辈的女孩子。

A 干女儿 is not your biological daughter, but a girl whom others regard you as a parent or elder relative.

在中国，很多人会给关系很好的朋友的孩子当干爸干妈，那个孩子就是他们的干女儿。

In China, many people become godparents to the children of close friends, and that child is their 干女儿.