Many mothers ask this question, especially when infant number two or three comes along: exactly how long should co-sleeping last? when will it end?
In my experience, age five (possibly by age four if there is an older sibling in the room as well), is an age where many children at least start in their own beds. They frequently then will come in when they wake up in the night.
However, even if children START in their own beds, they need to be parented to sleep. Most children like you to lay down with them until they fall asleep. This is the time of the day where your child may be most relaxed and will really talk about serious things that are on his or her mind. It is an opportunity not to be missed!! Most children who are aged eight or so can talk to you, cuddle with you, kiss you good night and then go off to their own room and crawl into bed and fall asleep. They still might like to sleep with you several nights a week if you are open to that.
I find most children sleep pretty well through the night typically around ages six to seven, unless they are sick.
I personally think one should keep a bed open to children as long as possible. If they want to be close to you, why deny the opportunity for connecting with them? Growing up can be scary and wonderful and challenging. Even a nine-year-old is still pretty little. Childhood is such a short time and being open to just being there and being available gives children such a comfort.
PS. And please don’t forget this back post if you need more: http://theparentingpassageway.com/2009/03/16/co-sleeping-and-nighttime-parenting/