Well, I know that my Dd took her primary aged 5. I have just looked at her certificates, she took RAD primary on 12/03/2008, she was born on 8/01/2003, that makes her 5 years old. And she passed with a merit and 71 marks.
She is taking her Inter- foundation in November, aged 11 and 11 months. She has been taking Inter-foundation classes since November 2011, and currently also attend Intermediate classes. She does three Inter foundation classes of 1 and a quarter hours a week and two Intermediate classes of the same length. She also attends 1 grade 6 class a week of forty-five minutes.
Her friend, who is now at White Lodge, took her Inter foundation with special allowances last July (she was 11 in the June, so therefore should not have been able to take it until the autumn term by rights).
Rightly or wrongly the RAD have, in the recent past, made exceptions. As I have said previously, I wouldn't necessarily advise taking exams early as the examiners tend to then Mark them harder. I am aware that an IDTA examiner last year told our dance teacher that some of the children had not achieved distinctions because she felt they were too young to be takin whichever grades they were entered for.