Since I began to write this post, I believe I’ve already answered my own question: What could make African Violet leaves curl under? I Googled the question and this would seem the likely culprit:
African violets grow best with daytime temperatures around 70-72°F and a night temperature around 650F. Night temperatures below 65°F produce malformed and discolored plants. Leaves curl under and become brittle when exposed to prolonged cold temperatures. In winter, protecting plants near windows from cold drafts is especially important.
Hmm. Poor Violet sits in front of the patio doors that lead onto the balcony — a spot that gets lots of indirect sun, but also a location that gets a steady mix of warm and cold. The heat radiator runs along the bottom of the door, and as the apartment is almost always too warm (from hot water pipes that run through the walls), we often have the door open an inch or so, even in colder weather.
But, even though this would seem a likely cause of Violet’s new curls, can anyone that grows these lovlies weigh in? Other than that, it appears healthy with lots of new growth. Poor Violet. Sigh.