Marie Lion's father was an engineer who built the first railway in the area near Pau, France. In 1881 Marie migrated to Australia with her sister Berthe and her sister's husband Nicholas Mouchette. She lived in Melbourne at 3 Nepean Tce, Gipps Street, East Melbourne and had a studio at 5 Collins Street, East Melbourne. Mouchette died, and the two sisters purchased the girls' school, Oberwyll, at St Kilda.
In 1892 Lion moved to Adelaide. Between 1893 and 1896 she tutored the children of E. W. Hawker at Mt Lofty, and by 1896 was living at Strathalbyn, South Australia. In 1895 she joined the Theosophical Society, and became one of the leading theosophists of South Australia. In 1900 Lion went to India. In 1906 she was living in 'The Lodge' owned by Sir Lancelot and Lady Stirling, and tutoring their children in French and the arts. In 1915 she returned to France for a visit.
As well as being a teacher of languages Lion was an artist, opening a studio in the National Chambers, King William Street, Adelaide, in 1916. In 1921 she was living in the Duncan Cottage Homes, 24 Prescott Street, Rose Park. She had pulmonary fibrosis for about seven years, and eventually died of broncho-pneumonia.
Her novel, The Black Pearl (originally Vers la lumière, 1910), speaks of her entertaining Annie Besant in South Australia.
