Should bed time be bed time or would you let you kids play quietly after being put to bed?

My fiance's eight year old tends to get out of bed and start playing as soon as her bedroom door is closed. Given a choice, she's play half the night...loudly.

Should we make her stay in bed or just tell her to play quietly?

(her bedtime is 8:30 pm / 9:00pm)
Update: I read to her for ages and she pretended to get all sleepy and snuggle down and go to sleep but no sooner I'm out the door than she's up and about.

15 answers 15