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.
An example of Bohemian style - my lounge photographed for the new Annie Sloan book Room Recipes for Style and Colour the Florence chalk paint wall has attracted a lot of attention to my home with the bold statement and bohemian vibe.
This is a beautiful idea as it doubles as a gallery for paintings and drawings with chalk frames & yet, lower down the wall, little ones can create their own spontaneous works of art! I copied it in my kitchen for my boy and he loves it!