I have created a new username for this post, so people can't identify me as a slushy Pollyanna 
Like Londonwillow, my DD is at Greycoat and loves it! She runs out the door each morning (early). We've been impressed with the school in every way. It's a very positive place.
When evaluating secondaries, friends suggested we go at the end of the day (not just on Open Days), to observe the typical atmosphere. At GCH, the girls all seemed happy, smiley, not at all cliquey. I'm happy to say that's been our DD's experience too. The other girls seem kind, friendly and open to new friendships. DD's fairly shy and was the only girl from her school to get in, so we worried she would struggle, but the school's induction day and general atmosphere of inclusion and kindness have helped tremendously. DD is really blossoming: trying very hard, progressing academically and feeling secure and happy socially.
The head seems very positive and friendly (observed at induction day and other events), but I suspect she runs an extremely tight ship – a great combination imho. The staff all seem happy, relaxed and genuinely interested in their students. It really is a wonderful place.
For the record, I do not work there or know anyone who does!

I sincerely hope your DD gets a place!
(wish everyone could who wants to go!)