My middle dd is 13. Having got off very lightly with teenage stuff with my oldest dd (15), dd2 definitely pushes the boundaries far more and likes an argument.
Her bedtime has been drifting later and later. I accept that she might not need as much sleep as I thought so I've relaxed a bit and aimed for between 10 and 10.30pm. She's fine getting up in the morning btw.
However, I've said to her that by 9.30pm her phone should be off and left charging in the kitchen and she should start heading upstairs. Partly because she needs some faffing time and partly because dh and I can spend a bit of time together.
So last night, we were watching tv together, I reminded her it was 9.30, she replied 'in a minute'. After a long moan about how unfair I am, I don't nag dd1 etc etc, she stomped off to bed and didn't come and say goodnight like she usually does.
I suppose I am a bit lax with dd1, she is supposed to be in bed by 11pm but she is also a faffer. But it's late by then and I'm going to bed myself.
This morning dd2 was obviously still in a mood with me 
So I don't know. When do you stop enforcing bedtimes? I know teens still need boundaries but on the other hand is this a battle worth fighting?