I did it. I kept several ferns alive for almost a year.
Mini-greenhouses and Wardian cases. Structures so forgiving that - as I ignored some of the plants during the excitement and zany-ness of Willa's first three months under my care - they still thrived.
The maidenhair fern really needed a tightly-sealed environment. Lots of humidity. The smaller greenhouse suited it best (bottom photo).
An asparagus fern, a bird's nest and two other smaller ferns took to the Wardian case like champs (top photo).
Now, my next step in this horticultural dance would normally be to push my luck and buy a few more. But I am so thrilled with this small victory, I am content to sit with it and just gaze at their greenery through the winter.