She currently serves as the General secretary of the South African Domestic Service and Allied Workers Union (SADSAWU). She also serves the first president of the International Domestic Workers Federation (IDWF), a membership-based global organization of household and domestic workers. Labor scholars have noted IDWF is the "first international labor federation run by women for work dominated by women."
In 1960s, Myrtle began her career as a young domestic worker in apartheid South Africa.
With the help of a local journalist, she helped convene the first ever organisational meeting of domestic workers in Cape Town in 1965.
As General Secterary of SADSAWU, she has fought for a national minimum wage increase and compensation for on-the-job injuries for domestic workers. In 2011, Myrtle helped lead the international coalition of domestic workers that secured passage of the International Labor Organization (International Labor Organization) Convention on Decent Work for Domestic Workers (C 189).
The Convention (Number 189) on domestic workers has become the first international labor standard to ensure domestic workers the same basic rights as other workers. As part of SADSAWU, Myrtle played a central role in influencing the International Labor Organization Domestic Workers Convention C.189.
The convention marked unprecedented involvement of informal women workers in the International Labor Organization standard-setting process.
In 2013, Myrtle accepted the George Meany–Lane Kirkland Human Rights Award, which recognizes international leaders and organizations who have overcome significant hurdles to fight for human rights.