As an 8 year old, December decided that actually she wasn't going to move away from California with her father and sister, but she was going to stay with her aunt. Her mother's dead, and not leaving the memories behind is her priority.
I'm more inclined to the view that children are involved in family consultation, but not decision making. But I'm also fully aware and fully annoyed by fictional fathers who are impossibly bad at caring for their own children, so: fine.
December grows up poor and her sister grows up rich, and its not really worth getting into. It's like if this was sort of the Parent Trap but the parents (or guardian) decided it was ok for one kid to be poor, and the protagonists know about each other and aren't identical twins. And while one of them goes to live the other's life, the other is just gone. And there's no possible romance or rekindling of feelings between the adults.
So not really at all like Parent Trap, I don't know why I brought it up.
When her sister disappears, December moves across country to live with her Dad, in the hopes that her sister will come home. She starts school at her sister's posh school where everyone is very rich and there's this secret society known as the Court. It's boys. And dads, but that's not important. The boys wear a gorilla ring and have special (non-magical) powers and a clubhouse mansion or frat house. They don't have to pay for the booze, and there are 20 dogs?
Girls can gain auxiliary power through a committed long-term relationship with a Court boy. They get a necklace and are referred to as Court Kept, and vomit this book should be all about tearing down this oppressive elitist system that is toxic lady-frenemy and also bad for the environment probably.
Instead, this book is about December's adoption of a random puppy and hiding it from her dad while making friends and ho girl enemies at the new school and having very little chemistry with the power sexy boy who helps her with pet care basics, like dog food and escaping a burning building.
The power sexy boy is Royal, and he's ok. I mean I'm now conditioned for hero boys to be beyond filthy to the heroine and he's not. Or at least not yet. He's a bastion of the oppressive elitist system, but he was also December's sister's best friend, so potentially helpful in resolving THAT mystery, but good luck if as a reader you're hoping for any plot suspense. Or for sense.
I mean seriously: the puppy. It just shows up. A pure bred lab, and no one is looking for it, and December doesn't think maybe she should try to find its owner? A chocolate Labrador puppy currently sells for $2k - $4k on Gumtree, and while that's Australian money and breeder prices you cannot tell me that in the US puppy finders keepers is normal pet rules.
The heroine's fitness as a pet owner is borderline at best, and her fitness to participate in her own plot is entirely too low. The book suffers from the need to maintain the fiction that the sister has disappeared but is not missing. It's a waste of time. The heroine is not a mystery heroine. Her approach to life is to show up and wait. Why is this a thing? Can't young people participate in their own stories any more, or at least ask some questions?
There are 3 more books, ugh I can't.