Esther's mother actually says relatively little to her, and this is part of the problem. There is a basic lack of real communication between mother and daughter. This was not an unusual dynamic in the time The Bell Jar takes place—the early 1950s.
The story reveals, apart from the details of Esther's illness, how much has changed since the middle of the twentieth century in our ways of dealing with problems, mental or otherwise, that young people encounter. Things which might seem common wisdom now were not generally recognized several generations ago. For instance, Mrs. Greenwood is clueless when asked about Esther's toilet training as an infant. She also tells Esther, "you're not like those people," meaning the other psychiatric patients. She repeats unhelpful truisms such as the idea that if one thinks about oneself too much, the solution is to think about other people's problems. By saying nothing but nevertheless letting out a sigh, Esther's mother expresses her displeasure that the psychiatrist, Dr. Gordon, wants to see Esther again next week. Esther tells us his fee is twenty-five dollars an hour, which, accounting for inflation, would probably amount to $400 today.
Esther's difficulties can be seen as resulting not so much from her mother's approach to the specific issue of illness as from Mrs. Greenwood's general attitude. She pressures her daughter in ways typical of ambitious parents of that time and later by saying, for instance, that for job opportunities, nobody wants a plain English major. Despite all this, it's unfair to put the onus of Esther's situation entirely or even mostly on her mother. Plath's overall theme in The Bell Jar may be that psychological problems are so complex that they cannot be attributed narrowly to a small set of causes.