I will give her credit for growing up really fast once the facts became apparent to her, but her behavior WAS reprehensible up until the al'Veres broke the news about the Aybaras. I guess helping one obnoxious teenager belatedly grow up makes up in some small way for not doing that at all for their own spawn.

But yeah. Pre-marriage, there was very little redeeming about her character. She abandoned her family and her responsibilities to indulge in adventures (and leaving her duty-bound parents and siblings to go about defending the world from the Shadow and poring over the accounts with a heavy heart imagining their eldest daughter raped and murdered in some ditch in the lawless and uncouth south). She then abandoned her Quest to chase a cute guy and intrude herself unwanted into his life, in a completely obnoxious manner. As I said in my subject line, she then treated Perrin's urgent need to protect his family as a game and way to inviegle herself into a relationship again.

I would like to think her PoV upon hearing the seriousness of the situation in the Two Rivers would have featured a colossal dose of horror and shame at her behavior to that point, and it is to her credit that rather than slink off in embarrassment, she mans up and makes herself be there for Perrin and support him and give him the occasional kick in the pants to do his duty. I think that moment had to be something of a crisis of self-reflection that illuminated her own delinquent behavior as well as her shabby treatment of Perrin, and caused her to start stepping up and understanding the importance of a leader's duty, so she could be there to provide Perrin the lessons he needed. They complement one another in that aspect, as he helps her learn the importance of duty and the need to adhere to it, while she helps him learn the specific acts and relationships which encompass duty. She knew what duty entailed, but lacked the virtue itself, while Perrin possessed the virtue very strongly, but did not grasp all the specifics of what was required to fulfil his duty as a leader.

I can get past Faile's bad behavior better than some other characters of the Egwenish variety, because she does improve and reform her ways and even step up to help others avoid her errors, and she keeps learning and growing.