I brought a new cat home recently. She was in her own room for about a week. I let her out to meet the others (two 4 yo cats) this past Sunday. There has been some hissing and chasing, but no real fights. I have still been putting new kitty back in the room when I am not home and overnight. Do I need to wait until there is no more hissing to leave her out full-time or do you think it's OK to do it now? One of my cats doesn't seem to have much of an issue with her at all now, but the other still hides a lot and hisses when she gets too close.