It’s interesting that you mention her manner of writing. I wanted to include this in my original post but felt it was getting too long to do so. One of the criticisms of her letters apparently has been her lack of coherence and elegance, so unlike her novels. Her slapdash manner of jerking from one topic to another has been likened to Miss Bates. “...when Emma mimics Miss Bates‘ ‘fly[ing] off, through half a sentence, to her mother’s old petticoat’, she reproduces Austen’s own epistolary use of the trusty dash that she applies in any direction to link together matters great and small....Miss Bates’ monologues, stuffed with roast pork and baked apples, chimneys that want sweeping, spectacles that need mending, sound suspiciously like her creator’s own prosey, rambling letters.

Caroline, it seems, was appalled by it: “It is this incoherence that so alarms Caroline Austen, who is looking for a proper ‘transcript‘ of an elegant, composed mind. In her letters, Austen employs a jolting, frustrating style which disallows for subordination. Dashes casually break up endless paragraphs to signal fresh ‘matters‘ inappropriately joined, subjects as momentous as ‘a dead Baronet’ and as mundane as a dose of rhubarb....”