You don't need a big space to make a special Mary-Mary garden. I made one in amongst the flowers in my 3 pots.
I find you can pick up little bird houses for very little in craft stores or garden stores, or you can paint any box you have lying around.
I 'wallpapered' my box with some origami paper I had left over.
Then I added some shells I'd collected at the beach, strung up some old necklaces for added magic sparkle.

Then I added the Mary-Mary dolls I'd made (see here for instructions) as well as some other figures I'd collected here and there.

A wonderful woman who reviewed Lulu Loves Flowers made an even smaller garden in one planter - one shaped like a stack of books:

Look at the tiny tiny silver bells!