I was discussingmy character history to some people and they though she should more like Chaotic Good instead of evil while she was in love and such. They said that since Love is one of the most selfless act you can have that she would be good in alignment. One person said the following to show that she was doing something good.
Rule of thumb.
1. If it makes people care about other people besides themselves in a way that is gentle, protective and forgiving = That's probably goodness.
2. If deliberately causes death, pain, selfishness, or greed = That's Evil.
Overly simplified and inaccurate. Don't listen to every shmuck who comes along. Love
can redeem, but a few good qualities alone doesn't make someone 'Good' per se, and neither is death, selfishness, greed, or necessary pain is instantly Evil. Take a man who kills an Evil monster in it's own lair and takes it's hoard for himself. He wasn't defending anyone from the monster at the time, he just wanted the riches. Thus he covered death, probably pain, as well as greed and selfishness in one go, but what he did was Neutral, since it's justified. He might even be Good as per the Aligment chart, though admittedly not the kind of Good I'd let hold my back. He could say the monster would have gone out and kill some innocents, yet by this reasoning he could kill anyone who sneers at him. In the end the deed wasn't bad, but the heavens aren't exacty going to praise him for it.
Conversely, You may call somebody a hero who saved a child from being run over on the street. He's still Evil if he, say, forces himself on women whenever he feels like it.
And then there is the housewife who goes and steals from the needy to feed his family and accepts the punishment when she's caught without resistance. She 'Cares about other people besides themselves in a way that is gentle, protective and forgiving' like you said, but screams of not being a good person. She still put herself and her goals(here, to protect her family) above everything and everyone. She is Neutral, at best.
Now, having cleared misconceptions out of the way... if the Succubus in question wants to impress her lover and acts Good for his sake, she is on the path of becoming morally Neutral, and
then may become Good, should she take a liking in it and start doing it for the sake of the deed. Maybe she just picks up Good qualities along the way and gradually becomes a better person. Both can happen, though neither is likely. It's entirely possible she stays Evil for the rest of her life, in love or not.