Between Brother and Sister

Some treasured, dog-eared letters have slipped out from the bottom drawer - their ink so faint, I am copying each one into my diary.
Mannheim, 15th November, 1777
Ma Plus Chère Soeur,
We have received every single e-pissle from Salzburg so please do NOT fret about old post.I’ve been to the closet this morning and am less full of rubbish. There is ice on the windows in Mannheim and I intend to accompany Mama by knitting in bed. Our same dear, saintly Mama has produced skeins of wool that she bought from Herr Hofmann and when we are fed up with the clickety-clacketing of our needles, she and I will play cards or tell our fortunes so we will all become rich. I am now off to the closet once again but would like first to ask if Pimperl has been snarling since I left? Do not answer that, because if she hasn’t, I will feel she does not miss us and if she has, I will be sad that she is. What a clever, subtle brother you have. I send you my latest Andante for my own dear sister to play. W.A.M.