Growing-Pains: The Greengage Summer by Rumer Godden (1958)

Thirteen year old Cecil Grey and her siblings, sixteen year old, Joss, ten year old Hester, and the littles, Willmouse and Vicky are taken to Compiègne, France one hot summer by their mother. Mrs. Grey whose husband is a botanist and is usually busy in expeditions abroad, feels that the children are becoming unruly and …