All this is happening in England, around 1860's. The characters aren't rich but not exactly poor, either. They have some wealthy relatives who could pay for the treatment if necessary.
So, here's the question. What can she do to get treatment for her brother? Could he be put under involuntary commitment, and if he could, what would the preconditions have to be? I've read that at least the legal process of making someone a chancery lunatic was long and very expensive, but is it the only possible way to put someone who was not a pauper (or a woman) into an involuntary commitment? What was this legal process like in practice?
Also, if someone could point out useful books or articles I'd be happy to read them. I have googled this with search terms such as "involuntary commitment 19th century", "history of psychiatry" and "chancery lunatic", and found some quite interesting websites, but I still have almost no clue about the actual process and the practical details about involuntary commitment.
My other possible storyline is that he is bribed and/or extorted to admit his madness and search for treatment himself, but I wonder if this idea is realistic at all, considering the stories we usually hear about the treatment of the mentally ill in Victorian times.