Dear Mister Moon (1998)

When two stepsisters - 13-year-old Sigrid and 7-year-old Saara - meet each other for the first time, it will turn out that their grandmother has been taken to a retirement home. The girls make up their minds to steal grandma from the home and hide her in an attic-room where they could be all together. Everything goes unexpectedly well until drunkards, hoodlums and blackmailers interfere and the girls have to know exactly what they are doing in order to escape the gang.