I've tried that putting her in a room that smells like Maya (which would be any room in the rest of the house). The only one that is easy to close, though, is the bathroom, and I did that for a bit, while I was in there with her, and even with me there she was crying and unhappy. She sleeps on my bed, and the bed clothes would be unwieldy. Right now I am trying to play with both of them at once (with a flying toy) at least one time each day. Maya still makes sorties when I have the door open, and the kitten races for her safe space, which is my bed. There hasn't been any more hissing, but Devlin is clearly terrified of her. Or maybe , scared but curious? Something like that.