mccombs became interested in socialism through the influence of her elder sisters, who were involved in the progressive liberal association, a small socialist-orientated group. one of the progressive liberal association's goals was to increase the political rights of women. mccombs herself became involved in the association, and as an extension of this, with the new zealand women's christian temperance union, run by prominent new zealand suffragette kate sheppard. mccombs held a number of positions within the temperance union throughout her life, including that of national treasurer.