Do it gently and gradually, and allow for relapses.
Don't worry or feel guilty - you haven't "spoiled" her at all, you've given her a wonderful gift. It won't become a "way of life" - they grow up way too fast and you'll come to miss the precious closeness.
I agree with what Danelle said (below), that you haven't done anything wrong. Our culture doesn't support bed-sharing with children, but there is significant evidence that it does much more good than harm and that "crying it out" can have long-term effects.
http://www.kellymom.com/parenting/sleep/familybed.html#links
I'm not trying to guilt you into continuing if you're ready to move beyond the family bed, I'm just saying there's no need to feel guilty about it if it's working for you, (meaning that everyone gets the sleep they need and has their needs respected.) Moms have rights, too, and if you're ready to move beyond the family bed, then it's time.
Inevitably, she will wake up and come to your bed (or want you to come to her.) You could start with different beds in the same room (having baby's crib within arm reach or just in the same room; or fixing a futon or bed for an older child on the floor next to, or at the foot of, the parents' bed.) We had a futon on the floor of his room where he could nap in the day, and either stay there or with us at night.
Then I took my child bed-shopping (he loved IKEA!)
and I didn't even buy the bed the first few times we went. He was hooked on one particular bed, and he was really BEGGING for it. So we made a big to-do about it. Fixed up the room a little, he got to pick out some cool sheets. We even took out some of the "babyish" toys to make it a bigger kids' room. And we made it perfect for storytime. (lamp, flashlight, and spill-proof cup of water on the nightstand.)
We read his bedtime stories there, curled up with him, and I usually snuggle him for a while after lights out, sometimes until he's asleep, but not always. Sometimes he sleeps there all night, sometimes half the night. Occasionally, he's in my bed before he even falls asleep once, but he's always welcome, so it doesn't become this big deal. The forbidden fruit, you know? (I was never allowed in my parents bed, and it became a big deal for me. I remember staring up at the ceiling too scared to move, imagining burglers and kidnappers coming though my window and stuff. No sandmen and moonbeams for me.)
It WILL pass, all too soon, so cherish this time. Think about how quickly she's growing and how much you will miss holding a tiny child when you are old and gray. (This hit home for me when I visited a nursing home and saw an ancient woman, maybe 90 years old, who constantly held and rocked a baby doll - those must have been her most precious memories of her entire life. I got choked up watching her. Sure reminds you of what's important in life.)