The title of the manuscript is "Biographical information regarding the Brewer family ca. 1917-1972," MS9352. I obtained a copy in 1999 of the pages that answered the question about Mary Ann Covington.
The title page of the manuscript is a dedication written by the author, "To my three girls, I dedicate this book that they might know the things of the past and preserve the things of the present for the future" The book of papers included a six page biographical sketch of Chauncey Walker West, who the author states was his grandfather. Then on pages 137-138 was a biographical sketch of Mary Ann Covington Stratton West. The details in the sketch that answer the question about her relationship to Chauncey Walker West include:
Mary Ann Covington was born 31 March 1815 at Bedford, Bedfordshire, England, the third child of Berrill Covington and Elizabeth Hodges.... She emigrated to Utah in 1847 in company of her husband, Joseph Albert Stratton.... They came to Utah in 1847 in Joseph Horne's company.... Mary Ann's husband died October 30th 1850 and in 1852 she married Bishop Chauncey Walker West and moved to Ogden three years later where she lived the rest of her life.... She was never blessed with children but she spent a life of service to her Church and her fellow man.
Mary Ann Covington Stratton West died on 5 Oct 1908. The second person by the name of Mary Ann Covington was born in 1841 and died in 1920. Both women were buried in the Ogden City Cemetery, located in Ogden, Utah. The second Mary Ann (1841-1920), had two children, Orlander West (1865-1866), and Milton Josiah West (1868-1937), both of whom were also buried in the Ogden City Cemetery.