I believe her works have undergone significant bowdlerization to remove racist references like golliwogs and stuff. Still don't know what a golliwog is. She had two school series called Malory Towers and St Clair. I think they were the best of the lot.
Apart from Enid Blyton I read all the books by Anthony Buckeridge too. They were 'school' books as well featuring the antics of Jennings.
To me Harry Potter is no different from those school stories. Similar kind of characters, good teachers, bad teachers, good students, bad ones, a wise principal, sporting events, midnight feasts- the works. Add in a Tolkien style fantasy-world and what do you have? Harry Potter! I am not saying that Harry Potter books are bad or whatever but just that they are treading well-trodden ground. Possibly because Buckeridge is virtually unknown in the US and most probably will stay that away, Rowling gets all the praise and kudos and what not for creating a fantasy world for today's youngsters.
Sometime back there was an interview with the creator of Jennings in the Daily Telegraph which came to similar conclusions that I had. And there is at least a few other people who share this opinion