In most games, Fleta is Evil, because she steals. Notice the good vs evil part for her. It's positive. She's got a kind hard, but is more or less the same as your average person.
Also, just a heads up - D&D itself states that the average person is True Neutral. It's a good idea to keep that in mind.
I also have a system that I use in my own campaigns to allow for characters to move outside of their alignment without changing their alignment. I took it out of "Heroes of Horror,"
Characters who claim to be good who start to do evil things like murdering, stealing arbitrarily, oppressing innocents, etc. start to receive points of "depravity." These points represent the guilt that normal people feel when they do awful things and it results in "penalties," like insomnia, a short temper, or constant sickness. Characters can remove these points by atoning for their crimes, BUT, even after they have atoned a fraction of the points still remain, because if you just do wrong and then expect forgiveness and then go out and do wrong again then you are not a good person you are just gaming the system. Characters who rack up enough points become effectively evil (i.e. they are subject to spells like protection from evil). Characters can remove the penalties entirely by changing their alignment to evil, representing a complete and total fall from grace.