One of the terms that demonstrate that there's an identity between the Star of David and Zion is the "Daughter of Zion". Originally it refers to the Temple Mount which is the "daughter" of Mount Zion.
During World War I a poster for the recruitment to the Jewish Legion was published in American Jewish magazines. On it there was a big Star of David encircilng a woman (Daughter of Zion) and the words in Yiddish: "Daughter of Zion I want your Old New Land! Join the Jewish regiment. On the head of this Daughter of Zion there's a stripe with a small Star of David on its center. In this case Daughter of Zion represented the Jewish people.