ok bec you can take over, its just too much lol
hahaha
well it looks pretty good memka! and just look looking at the corrections from droodles and ice_blockie i think it's pretty much all covered...
a couple of things though:
"elle a les yeux bleus et les cheveux blonds" is fine - you don't need to change that, they're both "les" (otherwise it doesn't sound quite right, almost as if she has "some" blue eyes and blonde hair)
"je la connais depuis année sept" is also fine:
you always need to use the present tense with the word "depuis" eg. "j'apprends le francais depuis 5 ans" means "I have been learning french for five years"
...if you've ever heard a french person say "I am learning the english since five years", you know why!
with the whole
"the group i sit with at school" part, i'd just simplify it:
"ma bande d'ami(e)s au lycée est...." (bande d'amis = group of friends)
one other thing, when you're talking about
the school you "go to" , it's "je vais DANS une école" - or in this case, dans un lycée. if you're talking about the place itself, that's when you use "à"
eg. je vais au lycée en bus = i got to school by bus
but Je vais dans un lycée grand. = i go to a big school
hope this helps, good luck with your sac