Who is Henrietta (Hattie) Dorsett from Sybil and what is their importance?

Henrietta (Hattie) Dorsett is Sybil's mother. She is a staunch woman, who came from a large family, and as a result, she was largely ignored by her mother. Because of this, Hattie was never nurtured and does not know how to nurture...... she is, in fact, extremely selfish.

Hattie suffers from schizophrenia, which was diagnosed when Willard took her to the Mayo Clinic in Rochester, Minnesota. Hattie, however, refused treatment. Unfortunately, her mental illness contributes to her horrific treatment of Sybil. After Sybil's birth, we get the distinct impression that Hattie never wanted children, especially, after Sybil's care was relingquished to Willard and his mother.

When Harriet took over Sybil's care, the child was exposed to unthinkable horrors at the hands of her mother who was mentally ill and unable to love. She even intervened in order to put an end to her own daughter's treatment..... something she professed to being proud of on her death bed.