She opened a dressmaking and millinery establishment and was enabled to give her children a practical idea of life and a fair education, and to make them self-reliant.

Marie's oldest sister, Lizzie, married A. Christie, a government surveyor, who one day announced that an American evangelist was holding very extraordinary services in the Free Kirk.

[1] In 1875, she married William Fitzjames Oldham, at that time an active layman in the church, who had been led to his religious life by hearing a few words of testimony spoken by Miss Mulligan, in a meeting which he had entered through curiosity.

[1] In 1879, her husband, believing himself called to the gospel ministry, prepared to leave India to fit himself in an American college for his life work.

[1] In one year, largely through the kindness of the women of the Woman's Foreign Missionary Society of the MEC in Meadville, Pennsylvania, Mrs. Oldham was enabled to join her husband in Allegheny College.

While there, she developed health problems, and after a few months of rest, she entered Mount Holyoke Seminary, in South Hadley, Massachusetts, staying until the spring of 1884.

Along with women of her union, Oldham was deeply interested in the welfare of English, U.S., and German sailors, visiting the saloons and persuading them to attend gospel and temperance meetings.