As far as I remember, they aren't ones we've seen before. I also found them on Google, though you have to search worldwide and not just UK (though curiously they seem to be on a UK site - don't understand that).
I was right about the History Room, and it also gives a date:
3rd March 1953: Girls in the upper fourth form of the girl's School at Christ's Hospital, Hertford, are given a history lesson by the author of their new history text book, Miss F M Page.
I thought it was probably just pre mid 50s as there is another one of the Dining Hall where the organ appears to be still there, and I thought that was put into the School Hall around mid 50s.
This URL might work better:
http://www.jamd.com/image/g/3404420
As well as this and the Home Economics one, there are
- two sixth formers working in the library,
- "Chemistry teacher Miss L M Wooton demonstrating a distillation experiment with girls from the upper fifth form at Christ's Hospital girls' school in Hertford"
- "16th May 1953: Schoolgirls from the Christ Hospital School, Hertfordshire, watch the boys from Christ Hospital School, Horsham, as they leave St Paul's Cathedral, London, after a Thanksgiving Service commemorating the 400th anniversary of the school's foundation"
- the one in the Dining Hall
It's a shame that the "Next photo" links don't seem to work on the JAMD website - I had to go back to the Google results every time. But definitely worth taking the trouble to look - nice photos, thanks Gerrie.