The Chalet School stories by Elinor M Brent-Dyer are good - a bit old fashioned, but nice stories. I think The School at the Chalet is No 1 - and if your dd likes them,
*@PurpleCloak*, there are 61 more, plus fan-fic fill-ins, so that would keep her going for a while.
Has anyone suggested the Gerald Durrell books? They are autobiography, rather than fiction, but are so funny - My Family and Other Animals is the first.
Another slightly old fashioned series, is the Lone Pine mysteries by Malcolm Saville - a group of friends who solve mysteries. Lone Pine Five is the first one.
The Swish of the Curtain, by Pamela Brown is about a group of children who find an abandoned theatre, get inside, fix it up and stage a play.
The Box of Delights, by John Masefield is a Christmassy book, but it is lovely - and there is a TV version (BBC, I think).