Thats a tough one Abb. My DD stuck with her friends from primary school when she went to HS with one exception who turned out to be a right little cow- that culminating in her mother screaming at me down the phone.
I have found that you really can't choose their friends and the more you dislike them the more she'll like them I found that by making it more difficult to see them (unable to drive her to their houses etc) but never saying anything negative about them it helped but really there's not much you can do.
I am lucky DD has lovely friends mostly and I get on well with them.
You will find at the start of HS your DD will prob stick with her friends she knows. Its such a scary time, I was pertified when I started high school! I cried every day LOL DD just breezed in and announced she loved it after day 1.