My daughter is in Year 13...had been a very positive experience for her. Pace of homework was very tough from the start of year7 which is not the case for all High schools or Grammar schools.
Good pastoral care. My daughter needed and was given some support/counselling very promptly.
Only criticism is that she hasn't been as happy there in Y12 and 13. The school doesn't quite make the transition to treat them as more independent students as they would in a separate 6th form college...having said that I'm really happy that she did stay on there as the teaching is excellent.
I went to wallington (left 6years ago eeek!) and it was a lovely school. If your dd is academic she will do well there, they don't cater so well for those less able (and by that they would classify B/C as less able!). My advice is don't tutor your child for the exam. If she needs help to pass the exam she is likely to struggle throughout her time at the school with limited support (or at least that's how it used to be!). If she can pass without tutoring then she will excel and it will give her a great start in life.