Hi, I suspect that you may have already referred to the pages below.
www.stcatherines.info/welcome/public-examinations
www.tormeadschool.org.uk/about/exam-results/
I would certainly caution against judging a school's performance purely on the basis of its exam grades, especially when the difference between the two schools is marginal.
Individual students at all of the Guildford girls' schools are sometimes limited in the number of GCSE and A level subjects they are permitted to choose. Would you judge a student who sat 9 GCSEs and achieved 5 grade 9s and 4 grade 8s to have done better than another who has achieved 4 grade 9s and 5 grade 8s and a 7?
Arguably those schools in thrall to the league tables are more likely to limit a student's subject choices in order to increase their chances of securing higher grades. Does this make them more academic?
To add colour to these exam results, it might be helpful to ask both schools
- what proportion of Year 11 students sit Additional Maths as well as GCSE Maths;
- what proportion of the Year 11 cohort sit 10 (or 11 if you include Additional Maths) GCSEs rather than 9; and
- what proportion of Year 11 students sit only Foundation level GCSE maths.
As the PP has said, the principal difference between these two schools is more in their atmosphere - traditional boarding -v- progressive day. I would go with the school where your DD feels most comfortable. If she is happy, she will thrive and do well.
Good luck with your research.