She ought to be shown past or mock exam papers. That's so she knows what to expect in the exam itself; exams are hard enough without being presented with the type of questions you've never seen before. She should have some practice in answering. Exams have time limits and some questions require all of a list of key points in an answer, but not other points. It is quite possible, without practice, to spend too much time on one or more of the questions or parts and be rushed to finish.That can prove costly. Answering all the questions briefly will get at least some marks for each whereas it is very difficult to get maximum marks on a few, and none on one or more and still get a pass. The best strategy is to aim to get a goodish mark on all, rather than waste time getting a perfect answer on a few and rushing the rest.
In short , get a tutor. They won't make your child cleverer but they will make her exam technique better and give her greater confidence.