Welcome to Your New Home
Having introduced more than a dozen foster cats to my home, I've become quite the expert on how to make the new member of the family feel comfy and secure.
New cats always gets their own room. It's outfitted with food and water, litterbox and toys. They are kept away from my resident cats until they're ready to interact. I regularly give them oodles of attention and playtime. Once they display more confident behavior, like freely moving around the room and sniffing at the closed door, I open their door a crack. Slowly, they emerge to explore other parts of the house. If stressed, they can always run back to their safe haven.
Introducing a new cat is an important process that requires patience and understanding. I tell all new pet parents not to skimp on either. The last thing you want to do is traumatize a new kitty in her new home. Comfortable kitties are happy kitties.