Thank you, Penguin2.
Tuxedo is still blessing my life and getting up to mischief. She is, though, appallingly thin. She hardly eats anything, but she does enjoy the jelly from tinned cat food (has always refused to eat the solids), occasionally has a teaspoonful of some ultra-expensive pate-type food from the vet, and still has a bit of kibble. I have a small tin of tuna in spring water for her tonight; maybe she will enjoy some of that. It's quite likely that my carpet will enjoy some of that, too, a few hours later.
Late evening, we have a cuddle on the couch. We have a nap for a couple of hours. She likes the cuddle, but I wonder if she likes the warmth too. I have got her a little heat pad, which emits very gentle warmth, and that's wrapped in a soft fleece blanket in her current choice of sleeping location. She seems to like that and spends most of her time there (can't say I blame her in that; it's been very cold outside!).
Her littermate Crypto, who always seemed a smaller skinny cat, now looks large and fat by comparison. She has also become more affectionate and touchable. I wonder what she knows, with her superior sense of smell. The two cats don't have much to do with each other, and seem more to tolerate than enjoy each other's presence. But who knows? Do cats mourn, in some way? Some do, I think.