There is a way out of the Manor in this room. You must go up 
the pull-down stairs in the ceiling. To reach the stairs, the
trunk must be moved below them. To move the trunk, it must be
emptied. The trunk opens with the combination to the lock. The
combination is on the right-hand wall in Nanny's room that is 
revealed behind a flap of wallpaper from a breeze when the window
is opened. You can open the window when you jump from the bed to 
the windowsill. Click on the trunk and the combination will 
automatically be entered.