Yes, I have.
I had a complete mental breakdwon when I was thirty-five, I was in a similar Victorian institution (the care is very modern though!) for three months, a year off work, and now, medication for life.
Severe trauma such as that suffered by sister's friend is a serious issue, but modern psychiatry and mdeicines are increasingly sophisticated. With correct medication, therapy and counselling, she will get her personality back, and slowly make her way back to the world.
The Victorians had the right idea - 'assylum' means a place of safetly and I had good rewason to be thankful for the tranquil secure grounds in which my hospital was set. At a time when crossing a road would have got me run over instantly, either as a suicide, or because I was incapable of assimilating something as complex as crossing a road, I was able to wander for hours in peaceful grounds with no danger of either getting run over, or bothered by the outside world.
The Government have, of course, sold the hospital, a wonderful Victorian institution which is now luxury flats, and the grounds, which are a housing estate, so I feel for the poor souls who cannot enjoy the peace and quit I had to aid my recovery.
Be patient, and this lady will get better, but it takes time, love, care, and treatment.
Hope this helps.