Images like this were often found on postcards.
On the left we see Gertrude and Ursula Falke.
Nepal and China
Left: A schoolgirl in Kensington, London.
Right: A group of children on their way to the Serpentine Lake in Hyde Park, London, in order to do some fishing.
Scotland and Ireland
The photo on the right is one of the first color photographs ever taken in Ireland, shot around 1913. It shows a 14-year-old girl in traditional dress.
Romania and Albania
The photo on the right shows two Albanian girls aged around 13-14. The girl on the left would go on to be known as the world famous Mother Theresa.
Left: Maiko girls (who would become geishas) relax on a balcony.
Right: Students at a school in Fukuoka, which was the first place to introduce the ’sailor-style’ school uniform seen here.
Argentina and Mexico
The serious-looking girl on the right is a 13-year-old Frida Kahlo.
Left: Two girls, Maria-Christina and Beatrice.
Right: The 16-year-old Federico García Lorca, a Spanish poet.
Poland and Estonia
The Estonian girls are imitating poses from a film, in an attempt to look like adults.
Greece and Cyprus
Left: A young Greek partisan, Konstantinos Mourikis.
Right: A class from the Maria Christodoulou School.
Austria and Luxembourg
Left: Prince Ernst of Hohenberg, one of the four children of the Austrian Archduke Franz Ferdinand.
Right: Princess Antonia of Luxembourg.
Australia and New Zealand
Left: A 16-year-old Walt Disney.
Right: A girl from the Kiowa tribe of Native Americans.
Brother and sister: Prince Leopold and Princess Louise of Belgium.
Sweden and Finland
The girl on the left is Princess Ingrid of Sweden.
On the right — a young René Lacoste, future tennis player and founder of the Lacoste brand.