Please help me find this book

Please help

Ok so what I can kinda remember is:
The main character is a Girl and she has a little brother. The live in the "New World" that is run by werewolves. She is alone with her brother because their mother died. She is barely surviving with her brother. One day she goes to school and she is taken by werewolves to be the alpha's mate? I think. The alphas name was Xavier or something. There was another werewolf but he was actually half human and his name was Nate I think. He brother was eventually saved. The main character was attacked a few times and was in the hospital a few times. She wants to escape the area she is in and another female werewolf trys to help her. But then there is an explosion at the school daycare that her little brother goes to and her brother goes missing because werewolves who don't like humans took him. I also remember her Alpha put her in a really nice Apartment with a bodyguard that she tried to kill once or something like that.

That is all I kinda remember. If I remember more I'll add on.
Please help ;-;