Among the Dolls — William Sleator

A dark awakening . . .

When her parents give her a gloomy old dollhouse for her birthday instead of the ten speed bike she's expecting, Vicky is disappointed. But she soon becomes fascinated by the small shadowy world and its inhabitants. The hours she spends playing with the dolls is a good way to escape from her parents's arguments. As Vicky's life becomes more troubled, she starts to take out her frustration on the dolls, making their lives as unhappy as hers.

Then one day, Vicky wakes up inside the dollhouse, trapped among the monsters she's created. Bewildered, Vicky is sure she's dreaming. Can she find her way out of this nightmare world?