She died in the night, and when they buried her it was eleven days later by the calendar and one by the clock: Spain had just adopted the Gregorian reform, and 5 October through 14 October of 1582 simply never happened there. So her feast sits on the day of the burial. The sources are calm about it in a way I find almost funny — nobody seems to have thought the gap needed explaining.
What I keep in mind about her is the practical side. Seventeen houses founded, most of them reached over bad Castilian roads by cart, and an unending correspondence with men who held committees about her. She wrote her own life down in a plain Castilian you can still follow. There's a portrait made while she was living, dated 1576 on the placard — dark veil, hands joined, a dove — and underneath it, her own signature: Teresa de Jesus.
The Libro de la Vida wasn't her idea — her confessors told her to write it, and she gets on with it like someone handed a form. Somewhere in there she apologises for her handwriting, something like begging pardon for the hurry and the blots, which is a thing I'd forgive anyone who wrote that much by candle.
Miriam, the Bernini version of her in Rome — finished around 1652 — has a trick in it most people miss: the light on her isn't the chapel's. There's a window hidden above the altar behind that broken pediment, glazed yellow, so it falls down the gilt rods and lands on the marble face. Stand off to the side and you can see the rods are just rods.