Not a pointless thread. Keep us updated. I really hope she isn't the sick one and I hope that person will help the sick one and get her treated - and the others if it is contagious.

Sounds like keeping her in your room with a big scratching post is a good start. If she doesn't seem to like the post maybe you could try the cardboard or sisal scratchers. With my cats they all like something different.

Looking forward to seeing pictures.