As for mocks, if your DD is sitting next month I'm not sure you'll find anything this late on.
However panic not. My DD didn't even do one and was fine.
it is not the end of the world if she hasn't done one.
Get your DD to do a "mock" at home maybe. I got mine to imagine she was in a classroom at Kendrick (they sit the exam in the classrooms not the hall). We didn't keep too quiet around her. Make sure she knows coughing, sneezing, maybe even crying and (hopefully not) vomiting etc may happen and she should completely ignore it. One girl in DDs room kept asking how to do questions as she didn't know. DD was able to ignore it however I guess others will have found it distracting.
Another poster suggested doing a mock in the local library as it is quiet, but there is enough going on around to add a little distraction for them to learn to avoid and it is not their normal environment.