If you visit their website, you’ll find a piece by Sophie Reynolds on one of Jane Austen’s rather more interesting correspondences, with James Stanier Clarke, the Prince Regent’s librarian. Theirs was a rather controversial relationship, and I’ve written about it in an article published in 2015:
Ingrid Tieken-Boon van Ostade (2015), Jane Austen’s correspondence with James Stanier Clarke. In: Emig R., Gohrisch J. (red.) Anglistentag 2014 Hannover, Proceedings. Trier: Wissenschaftlicher Verlag. 79-90.
And if you wish to read more about the language of Jane Austen’s letters, read my book on the subject. It was published by Oxford University Press in 2014. After reading it, you’ll find that you’ve truly got to know her!