I do want to know what time J got home and if he left again.
Do we know why he would be going to juvi? Do we have any reports of Child Protective Services being involved with this family?
There must have been a reason for Lindsey to be happy he was being taken away from the home. Most siblings would not want that unless their relationship was volatile (which a fight over his bike sounds like they had a bit of a rivalry there). Was this argument simply screaming at each other or did they physically get into an altercation? Was the person who sent him home concerned about the boy's temper for some reason? Does J lose control often?
I still have reservations about her brother, sorry to say.
I think my girls would be happy if their brother was leaving especially had he been aggrivating them. But when the time came for him to actually leave, then they would be upset. It would be hard to tell if it's normal sibiling rivalry or something worse without knowing more about their relationship.JMO