Reading Chapter 10 of Carol Ann Lee's book again Dr. Ferguson tells us he initially diagnosed her with schizoaffective disorder,which turned out to be mistaken as he later claimed she was suffering from paranoid schizophrenia. What surprised and shocked me was the doctor going further than what we already knew about her being obsessed with good and evil as concepts and the author quoting him as saying she had "expressed a measure of doing violence to her children..that she was capable of murdering them or communicating some ability for them to become evil or murderers at a later date."
I'm sure I hadn't read the above before in any of his four contributions in the Statements and Transcripts library. There is a footnote to the bit about Sheila needing evil to be cleansed in the CAL book but I'm not sure it extends to the part about her feeling able to murder them. When you look in the footnote the reference is Trial Testimony 1986,but I am unable to confirm exactly what he did say.