This is an interesting question. Hester is the antagonist in D.H. Lawrence's "The Rocking-Horse Winner," and she is a woman who has no discernible redeeming qualities.
Hester is selfish and cold-hearted, unable to love either her husband or her children. Presumably she does not love herself, either, but we find it difficult to muster up any sympathy for her. She is a beautiful woman who "started with all the advantages" and was able to marry for love; she has two beautiful children, and at least one of them is willing to die for her despite the fact that she is unmoved by his sacrifice. Nothing awful or extraordinary happens to change her auspicious beginning, so her becoming a miserable, selfish, and discontented woman is purely her choice.
Hester does not abuse her children in a traditional sense, but they are quite aware that she does not love them.
[W]hen her children were present, she always felt the centre of her heart go hard. This troubled her, and in her manner she was all the more gentle and anxious for her children, as if she loved them very much. Only she herself knew that at the centre of her heart was a hard little place that could not feel love, no, not for anybody. Everybody else said of her: "She is such a good mother. She adores her children." Only she herself, and her children themselves, knew it was not so. They read it in each other's eyes.
Her treatment of them is abusive in the sense that she neglects them. Things are worse for her son, Paul, once he begins to make money in an attempt to make things better for his mother. She may not know every detail of what her son is doing, but she is aware that he is not well and still does not care. When he dies after revealing the name of the next winner of the big horse race, we know that she is unmoved by anything but the money--and even her emotions about that will be gone soon enough.
Unlike Hester, the stepmothers in fairy tales are usually referred to as "evil." The stepmother in Cinderella, for example, is selfish like Hester, but she is also evil. She wants what she wants for herself and her daughters, for sure, but she wants it at the deliberate expense of Cinderella's life. She strips the poor girl of everything sacred: her memories of her father, her mother's belongings, and her future. In the end the stepmother's plans are foiled and she pays the price for her actions, but until then she is cruel, selfish, and unkind to Cinderella while her own daughters get the best of everything. Hester at least treats her children with equal disdain, and we have no sense that that she would have treated her daughter any differently than she did Paul if the girl had been the one making the money.
While Hester's abuse is shown primarily through neglect, Cinderella's stepmother's abuse is cruel and obvious, and this is the primary difference between the two women. The stepmother's selfishness and abuse is active, while Hester's selfishness and abuse is passive. In the end, of course, we get to see that the stepmother pays for her actions, but we can only imagine the life of continued misery and discontent ahead for Hester.