וַתֵּצֵ֤א דִינָה֙ בַּת־לֵאָ֔ה אֲשֶׁ֥ר יָלְדָ֖ה לְיַעֲקֹ֑ב לִרְא֖וֹת בִּבְנ֥וֹת הָאָֽרֶץ׃
Und Dina, die Tochter Leas, die sie dem Jakob geboren, ging aus, um sich unter den Töchtern des Landes umzusehen.
Rashi on Genesis
בת לאה THE DAUGHTER OF LEAH — so Scripture calls her. Why not the daughter of Jacob? But just because she “went out” she is called Leah’s daughter, since she, too, was fond “of going out” (Genesis Rabbah 80:1), as it is said (30:16) “and Leah went out to meet him”. With an allusion to her they formulated the proverb: “Like mother, like daughter”.
Ramban on Genesis
THE DAUGHTER OF LEAH, WHOM SHE HAD BORNE UNTO JACOB. The reason [Scripture specifies the daughter of Leah] is to state that she was the sister of Simeon and Levi, who were envious for her sake and avenged her cause. And Scripture mentions further, whom she had borne unto Jacob, in order to allude to the fact that all the brothers were envious for her.
Rashbam on Genesis
ותצא דינה, because Yaakov had pitched his tent outside the city limits of Shechem. She left that compound to enter the town.