Yes, the letter in the My Victorian/Witchy/Dark Academia Wardrobe (https://www.youtube.com/watch?v=6HXhW6nTCuo) video 12:06 , 12:19! And Cathy's comment ending with " PS. Anticipating receipt of your kind letter. Or was that for Aesthetics? 😜" Bernadette: "😏" (https://www.youtube.com/watch?v=6HXhW6nTCuo&google_comment_id=UgyUwV-Q8Itb6b_JTFJ4AaABAg) Also at 7:13 she shows off a brooch given to her by Cathy. The letter writing also appeared in some other recent video but my memory... haha.

Epistolary fic sounds lovely! I also loved the corset wrapped present.