Doll Bones by Holly Black
Definitely for Middle School readers, this a book about friendship and adventure - with very creepy overtones.
Poppy, Zach and Alice are best friends, and invent magical, fantastical adventures. In their constructed world, the Queen resides over the lands, a precious porcelain antique.
Locked safely away in the cabinet, the friends feel safe to give her powers to rule the kingdoms - but once they take her out, her powers seem real.
A twisted tale underscores the history of this doll; a father, a master craftsman used his dead daughter's corpse to create the doll. Her hair is woven from the remains of the girl's own, the limbs are made from bone china ground out of the little girl's skeleton, and her stuffing is a bag full of her ashes...
The friends are visited by her ghost in their dreams, where she demands to be laid to rest once and for all - or promises a deadly curse upon them all.