Louise Crummy was born on September 22, 1868, in Frankville, Ontario, into a pioneer family. Her father, Richard Crummy, left Ireland in 1842 to build a new life in Upper Canada, and 15 years later, brought Esther Empay over as his bride. Louise was born as the sixth child in a family of 10, and was the second of three girls.

She graduated from high school, and then attended Ottawa Normal School to obtain her teaching certification—though her real ambition was to be a doctor. At that time, it was almost impossible for a woman to go to medical school, so Louise, like many young women with dreams of other, less traditional, careers, settled for teaching. She taught in Ontario for four years, beginning in 1886. She then moved west to join a sister in North Dakota, where she taught for an additional three years before becoming deeply involved in the Temperance Movement.

In 1894, she became an organizer for the Woman's Christian Temperance Union (WCTU). While working for the cause of temperance, she met and married James McKinney—a kindred spirit, whose parents were also Irish Ontarians. They married in Ontario, and had one son, Willard, in honour of Frances E. Willard—founder and leader of the WCTU and one of the 19th century's best-known women.

The McKinneys moved to Claresholm, Alberta in 1903, and were active in organizing the first church in the town. Both Louise and James McKinney were raised as Methodists, and their faith played a central role in their lives—both private and public. When they took up residence in Claresholm, they organized church services, and two years after their arrival, helped to build the Methodist church. James taught a Bible class for Sunday School, and Louise filled the role of Primary Superintendent.

On the rare occasions that McKinney had time to enjoy a holiday, she was fond of travelling and sightseeing. Fortunately, she was able to combine this pleasure with her WCTU work, while attending the World's Conventions. She and her husband had the opportunity to visit Boston (1907), Brooklyn (1913), and London (1920). She also visited Lausanne (1928), as well as touring Italy and Switzerland. On her way home, she stopped to visit the White Mountains of New Hampshire.