She is absolutely beautiful! Congratulations!

But I echo everyone else's sentiment - please take her to the vet to have her tested for any diseases that could be transferred to your cats, and make sure she doesn't have any parasites they could get.

Once she's go the clear sign from the vet, you can do whatever you think is best to introdcue your cats to her. remember you know them best! I had the kittens in a cage in the room for a day and my boys sniffed at them. Some people keep the new cat enclosed for a few days and after the first day they bring out a blanket the new cat slept on for the other cats to get used to the new cat's smell.

Keep in mind that for the first few days, or even weeks, there will be a lot of hissing and growling. Thats normal.