The question really is whether you are ready to deal with a toddler getting out of bed a million times a night. she might not do this--my oldest daughter didn't, but my son did all of the time. I guess my oldest didn't realize that you could get out of bed, but my son had seen his sister get out by that time and knew that it was a possibility. We put him in his big boy bed at about 23 months, and he was out of that thing every two minutes. In the end, we told him that if he got out of his bed he would go to his crib, and he didn't want to do that. We did have to put him in the crib, which we had left up, and it seemed to deter his desire to explore!
It was very stressful and difficult, though, so with our third we have left her in her crib. She's almost three, and we are thinking about keeping her there for even longer. We bought a crib tent, which you zip up to keep them in the crib so they can't get out and fall, and she loves it. She thinks it's cool, and she wants to sleep in it, so it's not a punishment.
After my son was already in his big boy bed, I read in a book about kids' sleep habits that they aren't ready for a big bed until they're three because they are too curious and want to get out and explore on their own at a younger age.
I'm not saying don't do it without a doubt, but just think about whether you're ready to deal with a child popping out of bed every few minutes.