It can take up to 3 weeks for the hissing to stop, so be prepared to just watch them. Keep a squirt bottle handy. If the adults get a bit too rough with the kitten, giving a squirt of water and a firm "NO!" will teach them to back off.

Remember, you can't make them be friends; they will have to work that out on their own. Your job is to make them see they can all live together and tolerate one another.

Don't be afraid to use a time out if you have to as well. And THAT may be needed for the little one if she gets too exuberant. Just put the rowdy cat in a bedroom alone with the door closed for 5 minutes to cool off. I usually set the kitchen timer so I don't forget to open the door again.

I have 9 cats so I've done quite a few transitions. My longest one was 10 days. Oh, except that Crystal kept after Ebony for 8 months! Everyone else was fine with Ebony, but Crystal would hide in wait and leap out at her hissing and growling. And they are less than a month apart in age!

So sit back and enjoy watching the personalities express themselves.