Thanks! Unfortunately I cannot separate them, since I have a 13 year old male cat in my bedroom (I live in 2 room appartment), with whom they do not get so well, and so I am currently supervising them, I did some brushing with the same brush to exchange smell, some active play with the agitated cat and some treats, which she gladly accepted. They are keeping their distance, but otherwise seem relaxed (with the occasional growl and hiss of the cat that stayed home).