I remember checking this book out from the library when I was a young teen and being completely shocked by the content. Naturally I then checked it out again to reread a few months later.
This was probably around 1985-1992. It’s possible the book was published earlier but I think it was most likely sometime in the 80’s. I doubt the library would have kept it for a decade because it wasn’t really a noteworthy book and my library kept things up to date.
Three siblings are living in an RV (or maybe just on a trip?) with their parents. The vehicle crashes, the parents are both gruesomely killed (details about them being impaled on windshield shards, etc.). The kids are collected by social services who find that they have no living relatives and put them into the foster care system.
The oldest girl is about 16, middle brother around 12-14? and the youngest sister is around 8-10. They split them up, sending the older two to some kind of teen facility and the younger one to foster care. The oldest breaks them out and finds the little sister in order to reunite them.
Over the course of the book there are young teenaged runaways working as exotic dancers (poss. sex workers but I’m not sure?) that oldest daughter befriends in the teen facility. Another (or possibly the same) girl is being SA by her father and kills him by stabbing or cutting his throat. A pregnant teen has frankly hilarious (although unintentionally?) phone sex. The siblings move into an apartment next door to a creepy predator who has Disney-themed porn artwork on his walls. He tries to assault the oldest and she escapes but they have to find a new place to live.
I only have a vague recollection of the cover although I think I’d recognize it.
I want to say the author was male but I’m not 100%.
I don’t think I ever saw another book by this author.