A tween who cannot settle at bedtime is often one whose nervous system is still running high from the stimulation of the evening. Screens, social content, stimulating media, and unresolved social or academic concerns all keep the alerting system active well past the point where the body needs to be winding down. The inability to settle is usually an output of what happened in the two hours before bedtime, not the bedtime itself.
Your nervous system is still running. Let's see if we can help it shift.