Mary's ideas of the qualities needed for work among the ignorant and degraded may be gathered from a letter which she wrote at this time to a friend in Dundee:
Nothing, I believe, will ever touch or raise fallen ones except sympathy. They shrink from self-righteousness which would stoop to them, and they hate patronage and pity. Of sympathy and patience they stand in need. They also need refinement, for the humble classes respect it, and they are sharper at detecting the want of it than many of those above them in the social scale. I am not a believer in the craze for "ticket-of-leave men" and "converted prize-fighters" to preach to the poor and the outcast. I think the more of real refinement and beauty and education that enter into all Christian work, the more real success and lasting, wide-reaching results of a Christian and elevating nature will follow. Vulgarity and ignorance can never in themselves lay hold on the uneducated classes, or on any class, though God often shows us how He can dispense with man's help altogether. Then there is need for knowledge in such a work, knowledge of the Bible as a whole, not merely of the special passages which are adapted for evangelistic services. They know all the set phrases belonging to special services and open-sir meetings. They want teaching, and they will respect nothing else. I am pained often at home that there is so little of depth, and of God's word, in the speeches and addresses I hear. It seems as if they thought anything will do for children, and that any kind of talk about coming to Christ, and believing on Christ, will feed and nourish immortal souls.
In January 1884 she informed the Foreign Mission Committee that her health was re-established and that she was ready to return, and in accordance with her own desire it was arranged to make the house habitable at Old Town and send her back there. Meanwhile she had begun to address meetings in connection with the missionary organisations of congregations, and at these her simple but vivid style, the human interest of her story, and the living illustration she presented in the shape of Janie, made so great an impression that the ladies of Glasgow besought the Committee to retain her for a time in order that she might go through the country and give her account of the work to quiet gatherings of women, young and old. The suggestion was acted upon, and for some months she was engaged in itinerating. It was not in the line of her inclination. She was very shy, and had a humbling consciousness of her defects, and to appear in public was an ordeal. It was often a sheer impossibility for her to open her lips when men were present, and she would make it a condition that none should be in her audience. When some distinguished minister or Church leader had been requisitioned to preside, a situation was created as embarrassing to him as to her. She did not, however, seem to mind if the disturbing factor was out of sight, and the difficulty was usually overcome by placing the chairman somewhere behind. These meetings taxed her strength more than the work in Africa, and she began to long for release. In December the Committee gave her permission to return, but, as conditions in the field had changed, decided to send her in the meantime to Creek Town to assist Miss Johnstone, who was not in good health.