Define "tuffet"

"The conventional wisdom is that a precocious reader is a child in possession of a prenatural grasp of both the facts and features of the adult world. This may well be true of some, but was not true of me. My reading list didn't grant me access to the particulars of adult life, but to its moody interstices, the dark web of complex feeling that apparently suffused life after grade school. Like a child reciting nursery rhymes, I was consumed by the music of the words, not the circumstances surrounding Miss Muffet and her actual tuffet. (Well, can you, even now, define "tuffet"?)" --Lizzie Skurnick, from Shelf Discoveries