Living within walking distance of the National Gallery of Ireland, she spent a lot of time studying and copying the great masters.

[5] On her return to Dublin, Swanzy painted portraits and genre scenes and held her first show at Mill's Hall, Merrion Row in 1913.

This exhibition was reviewed by Sarah Purser who noted the lack of melancholy and light optimism in Swanzy's Irish landscapes.

After the deaths of her parents, Swanzy was financially independent and could travel, spending her time between Dublin and Saint-Tropez during World War I whilst continuing to paint.

Whilst visiting her sister who was involved with the Protestant relief mission in Yugoslavia and Czechoslovakia, Swanzy painted landscapes, village life, and peasant scenes.

These works were shown in the autumn of 1921 in the Dublin Painters' Gallery with six other artists including Jack Butler Yeats, Paul Henry, and Clare Marsh with whom Swanzy shared a studio.

As a result, she painted local tropical flowers, trees, and native women, with a palette and style similar to that of Fauvism.

She returned to Ireland in February 1925 and exhibited three of her Samoan paints at the RHA, and 14 at her one-woman show in the Galerie Bernheim Jeune, Paris in October 1925.