Yes, I was listening to Question Time on Radio 4 on Friday and was surprised by her comment. However, I was sure that when we visited the school, the then headteacher was talking about their charitable status and work. I have also known that the Corporation of London and banks funded the school. Anyway, a quick search reveals that they are indeed a charity.
https://en.wikipedia.org/wiki/City_of_L ... ble_statusDiane Abbott was criticised as she had made comments against private and selective schools, however, when it came to her own child, she sent him to City of London. That's why she said "As everybody knows...".
https://www.theguardian.com/politics/20 ... /labour.ukSalsa