Hi KK, I have a 13 yo daughter in 8th grade.
Last year she started the year as an Abercrombie poster child, and finished the year as well, somewhere between Emo and a Rocker (not wearing all black, with heavy black eye liner and such, but def went from 'pretty girl' to something entirely different.
This year, the hair is going back to normal (she's a natural blonde, she had it all black with a bleach blonde stripe) and she's moving to a more mature look). With out exactly encouraging her change of self expression, I havn't FORBIDDEN it either.
But she is an excellent student, has WAY too many friends, is not especially moody and enjoys school all through the 'change'.
I guess what I'm saying is the dsire to be different and change her look and attitude is very common for girls that age. To be expected.....
But a major change in attitude towards school and friends and a consistently different mood suggests there is more to it, you know?
Are you able to discuss what's going on with her in a non threatening way?
Until you find out what her mind set is, it's hard to say what her problem is.
Keep her close, lead her into communication by asking specific questions, by maybe showing her you can relate to whatever she's going through.
Hopefully it will just be a phase (I think EVERY child goes through a number of I HATE SCHOOL PHASES especially in middle school).
But if by the end of the year, it hasn't improved, I would probably seek out some help. I would probably take her to see someone. Maybe ask your ped for a referal.
Hope this helps!
:)