I think the introduction of Tabitha to my household can be deemed a complete success. She has just been doing the full kitten sprint around the house, paws thundering as only a kitten's can, while Robinson lay more-or-less oblivious in the middle of the hall. She just jumps over him.
Earlier, I had Robinson up on his grooming table in the study. Yes, the same study where Tabitha's litter-box and food and so on are kept. While he was lying on his side on the table having tangles pulled from his coat, Tabitha stomped in, ate, relieved herself, and then came and supervised the grooming. When a kitten is willing to use her litter box Right In Front of a Large Hairy Dog, I consider that we have at the very least detente, and very possibly armistice (appropriately enough for the season).
She is now lying opposite me on "her" couch, blinking owlishly.