Is talia al ghul a villain

No, she is not truly evil. The evil acts she commits are because of her loyalty to her father. She is torn between her love for Batman and her devotion to her father. She has shown that she has a good heart by helping Batman. Simply put, if it were not for her father, she would be a good guy and on Batmans side. Even with her upbringing to be evil, she still manages to do good. She could be defined as an anti-heroine.

But, recent events within comics show her as becoming evil, willing to have her (and Bruce's) son, Damian to be murdered.