Mag Chalkboard Paint: Paint a wall, have some craft activities to have her make castle/house/outdoors/etc pieces (modular ideas so she can build the castle in many different configurations). Also could use chalk to outline and draw.
This set of six retro kitchen magnets will brighten up your fridge door. Each magnet measures 1.25 inches in diameter. There is a strong ceramic magnet inset into the back (see last photo). They are capable of holding quite a few pieces of paper. The magnets are water resistant but not water proof. To clean them, simply dampen a cloth or paper towel and wipe clean.