You will be fine. If you have never ridden your bike 2-up, I will make some recommendations. First, double check tire pressures and chain tension. Also, you can play with the suspension if you want to, but not required unless your bike is lowered. Then I would suggest you at least raise back to stock height depending on the type of riding you want to do. I have scraped peg feelers with my wife on the back. Second, your bike will respond differently with a passenger. She will be a little more work, but it is really not bad once you get used to riding two up. Slow down in the turns until you get the feel of the bike, how it responds, and how much throttle makes the smoothest transition through the turns. Remember, you want to slow down before the turn, and power through smoothly.
You also need to establish some rules and signals. How much seat time has your passenger had? She cant be back there moving all over the place. She also will need to learn how to lean with you and fight you in the corners. If you lean one way and she leans the other, then makes a sudden move, it can be disaster. My wife and I use signals, two taps on the knee means hang on, I am about to boogie. A slap on the helmet means , boogie time is over, slow down! Her taping me on the side means go faster, etc. Ask anyone that has ridden behind me, they know when I am about to pass or take off by watching my wife and the signals we use.
Also, if this is the first time she has ever been on a bike, DO NOT SCARE her unless you want the first time to be the last. If you your knees or butt hurts, her will also, take breaks and let her stretch. If you truely want to share riding with someone, do it responsibly and have FUN!
I know I may have missed some stuff and I am sure others will help me fill in the blanks. Oh........if she is going to be a permanent rider with you, get an intercom. That also helps. If not, an MP3 player will make the ride more fun.