Not 12 as such but nearly - my 13 year old goes to bed at 9 p.m. when it's school next day, while the 11 year old goes at 8.30. We add a further 15 mins on per year, that seems to work for us, so next year our then 12 year old will go at 8.45. Our 3 are each spaced 2 years apart, so there is a half-hour gap between each going to bed - the 15 year old goes at 9.30.
Dds are 13 and 11. Bedtime on school nights is between 9.00 and 9.30 - if 9.30 it's lights straight out; if before they can read until half past. Ten-ish at weekends unless watching Lord Of The Rings or something!
ds goes to bed at nine on school nights - I don't give him a set time to go to bed at weekends but I ask him to go to his room at about 10/10:30 cos I eventually need a rest from him doing headstands, rolypolies and winding the cats up in the living room.
my nearly 12yo DS goes up at 9 and reads until 9.30. If he is tired he will go to bed earlier. Later if its scouts night as that doesnt finish until 9.15. So he goes straight to bed at 9.30-9.40 and is so tired he falls straight alseep.
My just 13 yo DD goes up at 9 spends half and hour in the bathroom, then wants to read. Lights out is 9.45 but she sneaks the light back on and reads until she falls asleep. (I'm not supposed to know this but she falls asleep with the light on )
8&9 year olds go up at 7 for a bath and story, lights out for them is 8pm at the latest.
Half nine on a school night, earlier if she wants to watch a tv show that i dont. Ten or so at the weekend, but earlier if she's tired or needs to be up early. Later if there's a specific activity/evening trip out etc. Never past eleven as far as I remember.
She likes her sleep or just pottering around in her room, so it's never been an issue.
tuesday is 10pm (she likes to watch CSI miami with me and DD1)
thursday is 10.30pm as she doesn;t get back from scouts until 10pm (officially they are supposed to finish by 9.30, but that never happens and I drop her friend off on the way back, hence the lateness). she comes home hungry, so she and DD1 (also a scout) raid the biscuit tin and have hot chocolate.
weekends is more like 10.30, unless they have a sleepover, and that could be anytime. (and they normally have a sleepover, altho 1 child rather than the ten we had this weekend).
my 14yo now has an open bedtime, altho she does have to go before me. she is learning that during the week, a later bedtime is not such a Good Thing, which means I am getting huge satisfaction from the arguements we had all last year that "EVERYONEELSEGOESLATER!".......