Glynne was born Mary Aitken[1] in Penarth, Vale of Glamorgan, South Wales.

She started her career in 1908, in a stage play called The Dairymaids at the Princes Theatre in Manchester.

A month later, she appeared on stage at the Queen's Theatre, London, in the same play.

Following her appearance in many West End successes, she toured the provinces and, later, South Africa.

She was married to Dennis Neilson-Terry,[2] who died in Rhodesia in 1932.