Sounds right on course to me. Only one hiss? No growling or swatting? Good! You're doing it right to do it so slowly and give them a chance to get used to each others scents. Phoenix sitting down is a sign of submission - that's a smart kitty you have there! Nakita is top cat - Phoenix is invading her territory. Slow is good. We'll expect some togetherness pictures in a month or so. My two are FINALLY getting snuggly after 3.5 years