My DS had some tuition for CRGS which was okay but he was very under-prepared for the English paper. He hadn't practised any classic texts at all so, when it came to exam day, he just worked his way through that particular paper as best he could. Luckily he did well enough with the VR and maths to make up for this and got a place.
We felt a bit let down by the tutoring because of this so I would definitely recommend practise with some classic texts over the Summer holidays. This standard of English is just not covered at primary level and is a good deal above what children are taught in Year 5. The maths exam is obviously at a higher level too but English, in my opinion, is more likely to catch students out.
Anyway, good luck for September and hope all goes well for you both.