Mary’s application to the Foreign Mission Board to go to Calabar was accepted. She travelled to Edinburgh for a three month training course in the skills that were thought to be important to become a missionary. Many of the practical skills that Mary already had as a skilled weaver and a resourceful woman having grown up in very difficult circumstances, were probably more useful for the life she was about to embark on.

Before she left Dundee, the congregation of the Wishart Church presented her with a gold watch.

On 5th August 1876 at the age of 28 she boarded the SS Ethiopia at Liverpool sailing to Duke Town in Calabar. The journey from Britain to West Africa in 1876 took roughly five weeks. Like most new missionaries at the time, she travelled, with set ideas about the work to be done and some misconceptions about the native people and their country. Many of these ideas were about to change.