I would examine her development in terms of her own self-perception as well. 

Scarlett does evolve throughout the story.  At the beginning of the novel, she identified and based her self-esteem on whether she had the right beaus or not, the prettiest dress, or the most admirers.

I agree with #2:  She does learn through the course of the novel to rely upon herself and perceive herself as a woman in charge of her own destiny.  It's straight up girl power, southern-belle style.

I would think that would not be too difficult to do. While I haven't read Gone With the Wind for years, my memory of Scarlett is that, at the beginning of the story, she is the stereotypical helpless Southern belle. As the story progresses and conditions deteriorate, she discovers strengths and abilities within herself that she never suspected she had - finding help for Melanie giving birth, protecting her property as best as she could, using her Southern belle training to attract the support and assistance she felt was needed to reclaim and rebuild Tara. The resilient and determined Scarlett at the end of the story was hugely changed from the girl at the beginning.