Our kitten Mickey is now 6 months old. It took about 2 months for Tommie and Gracie to realize that there was no getting rid of him!
There is still a daily wild rumpus, wrestling matches (with Tommie), and a little hissing and spitting (all Gracie). But at the end of the day, we find Tommie and Mickey cuddled up together.
Peace, for the moment.