Miles (née Squire) was born 19 August 1931 in Holywell, Flintshire, North Wales, daughter of James and Amy Squire (née Brick). She was the youngest of five surviving children. In 1939 she contracted cerebrospinal meningitis which left her deaf. She was educated at the Royal School for the Deaf and the Mary Hare School. In 1957, at the age of 25, she went to America to take up a place at Gallaudet College, sponsored in part by the British Deaf and Dumb Association. During her time at the college she became the first member of a junior class to be a member of the Gallaudet Phi Alpha Pi honour society, was in the 1961 edition of "Who's Who in American Colleges and Universities", edited the student magazines and won prizes for both her prose writing and poetry and for acting. Some of her work was published in "The Silent Muse", an anthology of selected writings by deaf authors of the last 100 years. She also wrote the Bison's song. She married a fellow student, Robert Thomas Miles in September 1958. They separated in 1959. She graduated in 1961 receiving a BA with distinction. She worked in the United States as a teacher and counsellor for deaf adults. In 1967, she joined the newly founded National Theatre of the Deaf and began to create sign language poetry that deaf people - as well as hearing people – could appreciate.