I'm going to play Devil's Advocate and say the family or sibling probably treated this person like shit and contributed to their desire to commit suicide. OP literally tells them to kill themselves and then further says they "wish brother would just get it over with" which is honestly a fucked up way to talk about someone's suicide attempt even if they're a money-stealing junkie or something. They would rather their brother die than annoy them. (As long as he dies quietly somewhere else.)
Trying to commit suicide in front of a sibling strikes me as a fucked up cry for help.
They don't give any context as to what motivated the attempt, nor do they specify drug use, but it's very disturbing to actually tell a suicidal person to kill themselves and strikes me as suspicious.