Christina Charlotta Hiärne was the twentieth child of Professor Olof Rudbeck the younger in Uppsala, came from a prominent learned family, suffered a religious crisis during her youth, and married Erland Fredrik Hiärne in 1745, who, like herself, was a pietist. In the 1750s, as members of the Moravian Church, they helped to establish the Swedish Mission Council in Stockholm.
Christina Charlotta Hiärne's only surviving son was a source of great concern to his parents. In her diary, she converses with God and Jesus and asks them to guide her son to choose the right path. Her diary, which she kept from 1744 to 1803, is available in manuscript. It contains a mixture of family records and religious contemplation, which, as the years progress, becomes increasingly more prominent.