I'm writing a novel, that is essentially about a world that does not live in black and white terms, but is always in the "gray area" (morality-wise) My main character is the typical anti-hero, you could say. She has a real problem with living in the gray area, and would prefer to be all "good", or all "bad". Since I'm working with a word count I've never done before (must be 65,000 words), I'm finding it a bit difficult to build up characterization. I'm afraid that she'll fall flat, or that I'll be unable to show her gradual changes. By 10,000 words, her dislike of "gray area" has been acknowledged, and to the reader's knowledge, she has chosen to be all evil. Upon meeting a man, at the 15,000 word mark, she teeters on the edge of evil/good, based on this man's influence. But, by the 20,000 word mark, she has returned to her evil ways. She will probably stay that way until 45,000 words, where she experiences her "life-changing" event. I hope I don't sound crazy, and maybe you guys don't have an answer for me, but how do I stop myself from making a contrived "suddenly, I'm good!" character. I really want to show the anguish.
Don't get too hung up on the word count in your initial draft. With experience, you'll develop a sense of how much story fits in N-thousand words, but for now, write the first draft of your story without watching your word counter. So write the first draft. If you are anywhere near your word count target (say plus or minus 25%), go ahead and do a revision pass to balance the flow, remove scenes that don't do anything for the story, and insert scenes needed for clarity. If your word count is way off, you may need to add subplots to increase the richness of the story, or remove complexity to focus more tightly on the main story elements. The above applies to ANY story. As to your specific question, observe people who have struggled with major dilemmas. Not only is there forward progress, there are always major, discouraging setbacks and self doubt.
It sounds like she's been thinking a lot about whether to be good or evil. She might have even thought too much about it, and ended up with the evil side. Give her a moment where there's no time to think - where she has to make a split-second, instinctual decision - and that's when, without even thinking, she does the right thing. But you should also give her a reason to care (maybe the man you're talking about?). Hypothetically, he could be tortured for doing the right thing, but he doesn't care since he's constant in his beliefs. She could watch this, and it could affect her. I don't know, that's just an example. I would also suggest some moments when she's "evil" when you can give subtle hints that her tough exterior is fraudulent, or starting to break down.