Why does the Torah refer to Dinah as "Bas Le'ah" and not 'Bas Ya'akov'?
Ramban: To stress that she was the full sister of Shimon and Levi, who took the lead in avenging her honor.
It is from here that the saying 'like mother, like daughter' arose.
Chachmah u'Musar (2 p.460): Leah went out for a Mitzvah, to beget a Shevet, and merited Yisachar. What is wrong with this?! It is because she took Rachel's Onah (time for intimacy). Even though Rachel consented, both of them were punished, and it caused pain to Yakov, and through the episode with Dinah, it was written about Shimon and Levi "Klei Chamas Mecheroseihem" - all for a minor misdeed!
After calling Dinah "Bas Le'ah", why does it add "Asher Yaldah l'Ya'akov"?
Ramban: Because all Bnei Yakov (even those from other mothers) displayed zealousness on her part to some degree.
Nidah 31a: Only Dinah is attributed to Yakov, to teach that if the man is Mazri'ah first, the child will be a girl.
Moshav Zekenim: The debacle was also due to Yakov. He was punished for hiding her in a box (refer to 32:23:1:1**).