Is this usual in Y8, or the sign of something worse?

[FiveHoursSleep]

DD1 is a bright girl and usually gets top marks in everything. Not necessarily 'the top', but near. She's in an academic, partially selective school so she's got some very bright classmates and very little disruption in class.
She's now in Y8 and has become a little less reliable. Not attending so many clubs and for the first time she has come home with 'not making much of an effort' and not fulfilling her potential' in one subject. The rest are making good and making excellent progress.
But if you talk to her she says she hates school, it's boring, doesn't enjoy anything. She's just 13 and has become a real teenager overnight- mouthing off, swearing, refusing to do things, whereas she's been pretty good up until now.
She still is doing her homework and music practice and seems happy enough with school although has a fairly good social life on and off line.
Her friends are very important to her but are all high achievers who work hard at school.
DD1 is our oldest, so I'm treating this as 'normal stuff' but keeping an eye on it. I don't insist she shows me her homework etc as the school will tell us if it doesn't get done.
Those of you with Y8 or older girls, is this all normal stuff?

DD1 was drifting in this direction a bit last year, definitely a combo of teenage hormones kicking in and yes, being bored. What saved her was choosing options - school does it in Yr8. She has been able to focus on the subjects she really loves and is completely back on track and more. She still explodes sometimes, is moody and a typical 14yo girl, but she is also showing an amazing maturity and work ethic.

I'd focus on setting boundaries for behaviour at home - swearing and unpleasantness just isn't on. Be firm, calm and consistent and keep talking to her. Keeping an eye is a good idea in any case, the teenage years are tough and you're the best ally she has.

I think it is a bit of teenage attention seeking. Girls seem to develop the 'I. Fail everything' mode when they are actually doing well. It gets them noticed. Are her friends talking in a similar vein? Try rewarding positive attitudes.

I've got a feeling that most of my year group turned into a pain in the neck in what is now year 8 - my whole class was put on report! I was at a selective girls school.

I'd come down hard on the swearing etc at home, but not worry about one subject being marked down. I remember having a bad comment for cookery on my 2nd year report and the form teacher had written "a good report but the Home Economics report is rather disturbing"! Erm no, I like eating food but have never liked the hassle of cooking it - many people enjoy the creativity of it, I don't.

As others have said, keep an eye on things but if homework and music practice are still happening without nagging, it does not sound like there is much wrong.

Year 8 is a funny year, I think. Students feel they have to act a bit more cool now that they are no longer the youngest in the school, and they've also discovered that detentions are not world-ending disasters. Plus they're getting more of a handle on the subjects that they like and are good at -- and those that they don't and aren't.
I certainly went off the boil a bit in that year and I do see it in my DS too. I've also noticed him trying out a bit of the school vernacular at home, which we stamped on pretty firmly.
By all means keep an eye on it, but she'll almost certainly get back to 'normal' next year.