Her articles, which were most competently written, ranged over a variety of topics from matters of domestic interest, good housekeeping, and the like, to a forthright advocacy of “women's rights”.
Her early journalistic sallies were sententious in tone, very much in accord with the literary conventions of the day, but her mature writing was concerned mainly with those issues which affected women's status in the home and community.
In this phase of her career Mary Colclough showed herself to be a woman with a practical cast of mind and of high ideals and principles, who was deeply conscious of the many social problems that called for urgent redress.
At the same time, she pressed for an improvement in the working conditions of seamstresses, shop assistants, and domestics, with adequate safeguards against poverty and the problems of old age.
She must have been a compelling advocate; according to contemporary evidence, “... one of the most fluent and accurate speakers we have listened to in the colonies.” In 1875 Mary Colclough began a campaign in Melbourne.
It is evident that her associations with the north must have weakened, for when news of her unexpected death reached Auckland in March 1885, it aroused little comment beyond the bald statement that her passing would be regretted by many who knew her in the olden times.