[1] For Chinese women, the Laotong or "old-sames" relationship was the strongest and most precious bond of female friendship.
If both children turned out female against the hopes of their families, the daughters could be brought together as Laotong.
An intermediary, in some places a matchmaker, would form a Laotong relationship between two girls, similar to an arranged marriage.
Laotong would frequently develop a language to use to communicate between them that only they could understand (a type of Nu shu), allowing them to send messages back and forth to one another.
These elements of the Laotong practise are shown in Lisa See's novel Snow Flower and the Secret Fan, which was made into a 2011 movie directed by Wayne Wang.