Merriman was born in Illinois, USA, on 19 December 1841. Her parents were Solomon Mitchell and Diana Thompson, and she was born on her father’s 300-acre farm near Waterloo, Illinois. When she was around eight years old, her family relocated to Lebanon, where they lived for about 18 years.

Following the passing of her parents, Merriman moved to East Carondelet, where she married Sylvester Merriman. The couple had seven daughters, but they separated after 12 years. Subsequently, she relocated to St. Louis, Missouri, where her daughters received their education. During her time in St. Louis, she found employment with the Grimm family. Notably, Charles Grimm, their son, was just five years old at the time and would later become a manager for the Chicago Cubs.

In 1927, she moved to Chicago. She continued working as a laundress until she reached the age of 75. By the time she turned 100, her eyesight had significantly deteriorated, preventing her from reading. In her younger years, she was a dedicated Bible reader, and later, she humorously commented that her frequent reading had taken a toll on her eyesight. At the time, she was still attending mass at least once a week. It was reported that she had converted to Catholicism in 1894.

Merriman passed away in Chicago, Illinois, USA, on 14 January 1954, at the age of 112 years, 26 days. She was survived by one daughter, Mae Kent (who passed away in 1982, a few days prior to her 100th birthday), four grandchildren, four great-grandchildren, and one great-great-grandchild.