About the ninth grade library: I would say no. An individual parent can decide to let he daughter read it but I don’t think the school should spend the money on it. This differs from the Holocaust, true events that happened, and written up in a productive framework.
I realize that there is a school of thought that says, let the school get it, let our kids read it, better this stuff than the YA wasteland at the public library. But some books just need to be read with the parents being aware that the child is reading it so they can discuss it. This series is fairly decently written but disturbing. In the first book, Innocent Deceptions, not a single deception was innocent. In this book there is, if imaginable, even more dysfunction, extensive description of addiction and exposure to the workings of AA, a very disturbing relationship based on a child bearing a name of an ancestor who’d been through is own gehennom and didn’t fully transcend it, and much more.
I don’t think any school library wants to get this and open the can of worms that won’t be opened from your typical soap opera or poorly edited and translated stuff. OTOH, I don’t think a parent who “lets” (because we know kids read stuff we don’t “let” them) her older high school girl read it is being derelict.