Depression and eating disorders run in my husband's family. His sister died from a heart attack at the age of 26 as a result of years of anorexia and bulemia. I've just seen that when one sibling is going through mental health issues, you really have to watch the others because it affects them more then you might realize. It's hard enough for us, as adults to handle things like this but when you are a kid....well...it's even that much more difficult. I don't know how close the younger two are to their half brother, but I think its them your daughter needs to think about.
Thanks for the advice. She is watching.....the oldest (a boy) has just started experiencing some signs of depression and our daughter made an appointment for him with a psychologist. This is part of what I meant when I said our oldest grandson is "toxic" to his family. It DOES impact everyone. He was psychotic for most of the time he lived with the family. We were just lucky that nothing too bad happened. I could curl your hair with some of the stories of the "almost" though.....