I DIE FOR THIS QUOTE! Will be doing this if my next little one is a girl! This is quite a spectacular room.for a small space! Any cool quote would work. ("Nothing is Impossible, the word itself says 'I'm possible'-- Audrey Hepburn)
This is a perfect combo of my two favorite ideas for that space under the stairs leading to the basement. A reading nook AND book storage and shelves . assuming that there is enough space for this there.