Sleep problems in children are common, and in rare cases physical causes play a role. Of course children can sometimes be ill, an ear infection have, or are busy in their head. But that lasts for weeks and can always be traced back easily. Childbirth or the cervical spine will not be the cause.
Much more often it has to do with a learned pattern: the unwanted behavior has ever emerged and remained in position in some way. Sometimes a role as also playing attention giving a positive stimulus. For this you must know exactly what is exactly happening at bedtime.
I suspect that a child psychologist to figure out why the behavior of your daughter not changed and they do not sleep in her own bed. The action to be taken are often not as complicated and much to my surprise, the problem solves it in a very short time