Hi there! Congrats on your new kitty adoption! Absolutely! Take things slow. It's very normal for your older cat to be a bit out of sorts with a new member in the family. I would suggest keeping the kitten locked in a separate room for at least a week to allow them both to smell each other just through the cracks in the door. Not to mention give the new kitty time to settle in. When they do start to make contact, your older cat will likely still hiss and want her distance which is completely fine. Never force contact and allow your older cat to decide when she is done socializing. They will certainly learn over time to get along, or at least tolerate each other. Animals usually have a way of finding a place and making it work. Good luck!