OFSTED Outstanding Head espouses creativity

In the UK schools are formally inspected every three years and the resulting reports are published online. The Daily Telegraph, a UK daily newspaper, had this to say about the Headteacher's approach to getting the best out of her pupils:

This is not a traditional grammar school. It's not regimented or restricted or restricting. ... I never say that we will help the girls reach their potential because we don't know what their potential is and nor do they. We urge them to try things out and take as many opportunities as possible to find out what they like and how far they can go.

The phrase "we don't know what their potential is and nor do they" leapt out at me. So much intake to educational institutions is based on the quality and intelligence level of the intake that a phrase like "we don't know their potential" seems absurd. Yet this is a highly rated school, with students impressing government inspectors.