Concerning Charlotte Ernst, the sister of Wilhelm Schlegel and Friedrich Schlegel, see the following documents.
(1) Friedrich Laun, Memoiren, 3 vols. [Bunzlau 1837] 2:3–4:
Among the many bourgeois families that offered a welcome refuge for conviviality and respectable mirth in Dresden, the Ernst house stood at the very top of the list. The head of the household, Court Secretary Ernst, who took a zealous interest in learning and the arts, took the entertainment of his guests quite seriously indeed. His intelligent and witty wife, sister of the Schlegel brothers and an exemplary mistress of the house, provided excellent support for him in this regard. Indeed, I owe many a delightful evening to this house, which enjoyed the not inconsiderable advantage of providing one with the opportunity of socializing with the Schlegel brothers whenever they were in Dresden, as well as with Tieck and various other distinguished scholars and artists.
(2) Henriette Mendelssohn to Dorothea Veit on 19 April 1799 (letter 230e):
Charlotte is a magnificent, truly singular person; [Friedrich] Schlegel told us much too little about her. She is an animated, amiable spirit and speaks quite sensibly and wittily. Her eyes she has from Friedrich, the rest of her features from Wilhelm. The tone of her language and the way she expresses herself is an equal mixture of them both. I am uncommonly pleased with her, as you doubtless are as well.
(3) Dorothea Veit to Karoline Paulus on 26 October 1804 (Briefe von Dorothea und Friedrich Schlegel an die Familie Paulus 29):
Apart from Friedrich’s sister Charlotte, I have never loved a woman as much as I do you. Charlotte is an excellent, extremely respectable woman; I wish you were acquainted with her, she would doubtless also love you as well, though she would perhaps not be as in love with you as I am!
(4) Friedrich erected a monument of sorts to her in his novel Lucinde: see Isaac-Julien Rouge’s discussion in supplementary appendix 209.1.
(5) Schleiermacher to Henriette von Willich on 21 February 1809 (Friedrich Schleiermachers Briefwechsel mit seiner Braut, ed. Heinrich Meisner [Gotha 1920], 346):
The character of Ernestine in the letters [Vertraute Briefe über Friedrich Schlegels Lucinde (Lübeck, Leipzig 1800)] and in Christmas Eve [Die Weihnachtsfeier: ein Gesprach (Halle 1806)] are to a certain extent one and the same person. I cannot say that I was thinking of anyone specific, I know only that a certain image of one of Schlegel’s sisters in Dresden was hovering before me that I construed after hearing various stories about her, stories which, however, were perhaps not the most accurate.
(6) Wilhelm von Chézy, Erinnerungen, vol. 1 (Schaffhausen 1863), 173f.:
Ernst was a good, hen-pecked husband whom Callot-Hoffmann somewhere introduced by name, delectably characterizing how Ernst, intimidated by his wife’s admonishing look, backs down as he is about to fill his glass with mulled wine and instead steps over to the wall cabinet, where, hidden behind its door, he gulps a glass of caraway schnapps. [References to Charlotte being remarkably miserly despite being quite rich.] Apart from all that, in her company one could hardly imagine anything more pleasant than this elderly woman; whenever she began to chat while knitting socks with her fingers bent by gout, one could easily listen to her for hours. She loved to tell stories, and those around her never failed to enjoy it when she did.
Finally, it is worth pointing out that, unfortunately, Wilhelm Schlegel firmly directed her daughter, Auguste, to burn his letters to Charlotte after her parents’ death. (Auguste von Buttlar to Wilhelm on 30 July 1826; manuscript: Dresden A).