Weeeellll - somedays Miss Scarlett will tolerate Sarah, and some days the hissing and spitting goes on frequently. I did see (I swear!, I swear!) a moment when Miss Scarlett actually played with Sarah! I swear, I did see it! :)
Otherwise,Sarah is growing fast, and is now almost 5 months old. She will be neutered next trip to the vet (in about 3 weeks), then I shouldn't have to take her back for another year. The vet thinks she's going to be a 'dainty little cat', which will be a change from all the very large cats I've always had. She is currently only half the size of Miss Scarlett, who is a lean cat at 8 pounds. Big, muscular and lean, just like her brother, who measured 40" when fully stretched out.
Sarah is in constant motion, and is free with claws and teeth, a habit I am trying to break. It's slow going, but she is learning to not use them. I am also trying to break her of using the furniture instead of the scratching post. But since I'm not home most of the day, I'm not getting very far with that. Sigh.