A few thoughts I had for you...
If the main motivation for you wanting to transition her to her crib is safety, please know there are many safe ways to co-sleep. You can place your boxspring and mattress on the floor, shortening the distance to the ground. If you place it along the wall, baby can sleep between you and the wall safely. Babies learn quickly how to back down off the bed without being hurt. Others mentioned safety rails and even using the crib alongside your bed, all of which are great options. We have never had any issues with our children falling out of our bed.
If you are interested in making the transition, a few suggestions.... If you are trying to transition her off nursing to sleep while also transitioning her from your bed, I would pick one to focus on first. Maybe help her learn to sleep without nursing in your bed, and then transition her to her own bed. It might be very hard for her to try to lose both of those comforts at once.
Using the crib as a sidecar can help to ease the transition since baby will get used to sleeping in that space with you near before you set her up with the crib on her own.
There are so many approaches, and I don't know all your parenting philosophies, but it seems to me that since you have chosen to nurse and cosleep you might be happier with a slower, more gentle transition. Sleep can be such a battle but it doesn't need to be if we remember how short a period it is that our children need us so intensely.
Good luck and happy sleeping!
A.