first...do what works for your family. If you want to co-sleep, then continue doing it. If you wish for your daughter to be in her own bed then start the process and bare n grin sleepless nights and several wake ups from her. Its ultimately your choice where to begin. Think long and hard the pros and cons of each.
I have slept with my son since he was a new born. Also my residences created me to continue sharing a bed with him (very small 1br apt all i could afford to rent). However, co-sleeping allowed my son to sleep throughout the night. Which means mom slept well too.
When I introduced my son to his own full sized bed at 7 months, he woke up 3 times a night. He would crawl out of his bed (it was on the floor with no box spring) and crawl to mine crying! he would be rocked back to sleep and immediately put back to his bed.
My son is 3 now and in his own bed. He sleeps in the same room as I do as I rent a 1brd. he goes through waves where he will wake up a few times a night wishing to be in bed with me. Other times he sleeps throughout the night.
The key thing here is consistency! Baby steps first...slowly working into bigger things. For example:
Start bed time an hour earlier then normal. I recommend a toddler bed. You start off in her room, in her new bed. Giving her choices to bring a favorite toy or blanket with her. Read a book. Sing songs, play music, laugh. Make the experience of being in her own bed fun! When her normal bed time comes near, 15mins before hand tell her when she falls asleep, mommy and daddy will be in the next room. Also communicate with her that if she needs mommy and daddy, she is welcome to come into your room, but not your bed. Then stay in the room with her until she falls asleep.
If she wakes up in the middle of the night (usually 12:30, 2:30 or 3:30a) and you can make it into her room before she gets out of bed, then reassure her everything is okay. Encourage her to stay in bed. Tell her she is a big girl. Positive reinforcement. If she cries, stay with her til she settles down. Then help her lay down. Give her a kiss, say good night and you love her. Walk out, turn around, blow a kiss and say see you in the morning (if she reacts in crying again, go back in and settler her down). You will have to do this for a bit...slowly working your way out of the room before she finally goes to sleep (I usually walk out of the room 10mins before my son actual bed time).
I found the best results with this. In the beginning they need reassurance you will be there for them. its scary for them at first. All they know is the comfort and security of mom and dad being beside them when they open their eyes. Its like abandonment.
Make sure anyone who cares for your daughter follows this ritual you have set. As any break in it can send her back. Remember too, there will be waves of time where she will wake up several times a night crying for you. this is normal. Teach her to self sooth or call you from her room and not get out of bed, to also use her words, not cry.
Again, do what works for your family. But remember, if you allow her in bed ONE time with you due to lack of sleep, she WON. Then you have to start ALL OVER again. I learned the hard way and set myself back a dozen times. Sleep was more important haahaa...but over time my patience wore thin of dealing with waking up 3 times a night dealing with my son to b in my bed.
Lastly, i never believe in the cry out method, not even when it came to training my son to stay in his bed and go to sleep in a toddler bed. Get a favorite toy and keep reminding your daughter that toy is there for her when she gets scared. To hold it tight.
That helped my son. He has a few stuff animals who he sleeps with plus a few toys of his choice, a star/moon light turtle, a space rocket (shows the plantes, moon, earth) and music playing in the background. Anything to make bed time enjoyable and easy to make him fall asleep on his own.
This did not happen over night!!! It takes time...a minimum of 2-3 months...if not longer depending on the child and parents.
Good luck!!! take naps if you can due to the lack of sleep...lol