Esther can't stand her mother, Mrs. Greenwood, but considering all of the awful mothers in history and literature, Mrs. Greenwood doesn't seem all that evil. Classical Greece gives us Medea, who slaughtered her own sons in revenge against her cheating husband. Alfred Hitchcock gave us Psycho (cue the scary music). And Disney gave us Cinderella's wicked stepmother. Against these maternal monsters, Mrs. Greenwood looks positively angelic.
But maybe that's Mrs. Greenwood's problem. Perhaps Esther despises her mother because her mother represents all those traditional expectations for women that Esther is desperate to overcome. There's some suggestion that Mrs. Greenwood's marriage to Esther's father was lacking in the romance department, and Mrs. Greenwood took on the role of a wife and mother, with no career of her own. Even when she did get a job after Esther's father died, Mrs. Greenwood chose to teach shorthand, a secretarial skill to help women take dictation from men. All practicality and sensibleness, Mrs. Greenwood seems to have little sympathy for Esther's literary aspirations, and she views Esther's nervous breakdown as a moral failing, not a serious illness.
In short, Mrs. Greenwood seems to want Esther to fit into a cookie-cutter image of the ideal 1950s housewife. And for Esther, that's the equivalent of a living death. No wonder, then, that Esther seeks alternative mother figures in characters such as Jay Cee and the much more sympathetic Dr. Nolan.