Re: the statement about schizophrenia it can often start in later life eg onset 30s for her and her Father
Schizophrenia developing later in life is very rare - most people have their first break aged 16 - 25. It is really unlikely you will become schizophrenic if you've made it to your thirties. That is not to say you cannot have a psychotic episode.
Then again, like all MH issues, some of the elements that make up psychotic illnesses (strange non mainstream ideas, paranoia, disconnections with reality, delusions) may well be present in people who would not meet criteria for diagnosis - they might otherwise be seen as eccentric.
We cant discount class here either - the upper classes have a long history of not being so bothered about what other people think of them, or resisting normal social conventions. It is equally likely, imo, that CM just has a long history of going her own way - as a PP has said, also something seen a lot in people who gravitate to new age ideas.