Children’s fiction book set during WWII in England. A group of evacuated children, abandoned or lost are hiding from enemy troops in ruined building or cellar in rural England.
The oldest girl is the “mum” taking care of the little ones. They make it homely using stencils of pineapples? (that may be a different book?)
When they are finally rescued by friendly troops, they are given treats by soldiers: a bar of chocolate and one orange to share between them. The youngest girl slowly unwraps chocolate foil like it is priceless treasure, but ultimately decides the orange is the best thing she has ever eaten.