I would consider her treatment of her children when she is alive as kind of begign neglect. They don't seem to be suffering for the way they are treated. Each year I have students comment on the fact that they will be stronger for it, and they use as proof the description of the son who falls down but gets back up, refuses to cry, brushes himself off, and goes back to his playing. Edna is certainly not the mother-woman ideal, but that is just not her. On the other hand, her leaving her children motherless with her suicide is where I lose my "sympathy" for her. I can appreciate that she feels she will be a better person, better mom, if she can be something of herself first, but the suicide is a selfish childish act and I while it is an excellent, fitting ending to Edna's story, it is not ok for the children.
I have some sympathy for Edna, in that she was born in a time when women had less say about who they married and what that marriage looked like. Given that, once she was married, she was neither a particularly good wife nor even a marginally good mother. Those are choices she made which do affect other people--and especially her children. Other choices she didn't have--this one she did. I do sympathize with the feeling of loneliness and longing and a wish for something more; however, she had responsibilities which she had an obligation to fulfill and she didn't do it. I have no sympathy for that.
I agree that the children are the innocent victims in the story, thus making Edna a more sympathetic character because she feels that she must treat them in such a way in order to find her sense of individuality. If we assume that Edna truly loves her children, then her sending them away may be considered a complicated sacrifice that she feels she must make in order to attempt to pursue the life that she really wants.
This question is perhaps better suited for the discussion boards, because it is somewhat an opinionated question. In my view, no she should not be sympathized with, especially when it comes to her treatment of her children. She viewed them as things to entertain her, and when they were no longer amusing to her, she sent them away. While it is a book about finding one's self and abandoning the oppressive traditions of society, Edna's pursuit of her own life and happiness causes her to alienate her children, eventually leaving them without a mother. It has always seemed to me that they are the innocent victims of the story, which is what motives the admonition to "Remember the children."