Horner was a first cousin once removed of the British Theravada monk Ajahn Amaro.

In 1921, Horner traveled to Ceylon (Sri Lanka), India and Burma where she was first introduced to Buddhism, its literature and related languages.

In 1943, in response to her parents' needs and greater PTS involvement, Horner moved to London where she lived until her death.

In 1964, in recognition of her contributions to Pali literature, Horner was awarded an honorary Ph.D by Ceylon University.

[8] In 1980, Queen Elizabeth II made Horner an Officer of the Order of the British Empire (OBE) for her lifelong contribution to Buddhist literature.