This ‘incident’ (about 23,000 words) is from 1804, a series of letters from Ann to Julia during the time when Mrs. Northcott dragged Ann to Bath for failing to flirt effectively with Lord Merivale. It was an indirect result of this trip that Mrs. Northcott came up with the idea that eventually sent Ann and Julia and the rest of the Parrys to London the following year.
Note: Right now this is only available as an ebook. If I can find enough short incidents “in my grandmother’s trunk” to cobble together a few more stories I will probably put them together in print some day. (FYI: the desk shown on the cover once belonged to Jane Austen, apparently.)