Firstly many thanks to all have me so much advice 
head of science phoned this morning. He explained that in Y9, there will be 6 sets rather than 2 top, 2 middle and 2 bottom sets, so DD should naturally move out of bottom set. In the short term, they are going to let DD resist her end of year test.
I have pointed out that she may have gaps in her knowledge due to the teacher having to "crowd control" the class. This teacher has now left the school. - He is going to phone me Friday and let me know which set she will be in. he did mention she gained some level 5s on some of her tests.