or an improper lady!
My grandmothers were old enough to tell me that crossing your legs at the knee is seductive and flapper-ish. (Which one of them approved of.)
The primmer one crossed her ankles, and the really old-fashioned one had been taught to put her ankles together and possibly, possibly, bring them to one side when putting them under the chair. The interesting thing about ankles-together is that it feels like a very gentle yoga sit to me, good for my RSI and the rest of my posture.