Well that 'one day' has arrived.
I bought a box of Altoids, and they are indeed curiously strong mints. Powerful might be a better term.
We glued a piece of felt on top and she decorated it with felt flowers.

Next, we cut out a piece of white brushed corduroy for the mouse body, I stitched on the face and limbs, ears and C stuffed and stitched it closed. We also made a tiny pillow and blanket.
There is an excellent tutorial to make a pocket sized mouse house here
I bought 2 boxes of Altoids so perhaps we'll make another little pocket sized house for a tiny bear next.