When Mercedes was 17 years old, she met an 18 year old professional piano player by the name of Leroy (Buddy) Davis and the two were married about a year later. Of this union were born six children. Around the year 1965, Mercedes accepted employment as a computer programmer for Honeywell, Inc. She would work there for the next 14 years until health issues forced her to quit that profession.  Later, when she regained some of her health, she worked part-time as a tax preparer for H&R Block until her health, again, took a turn for the worse. Instead of letting her health issues get the best of her, she became a "best diet for Mercedes" expert and pulled herself back. However, her type of physical illness was naturally degenerative and she became progressively worse. Still, up until the time of her death, she kept and managed the financial books of two churches.

Early in her life, Mercedes accepted Jesus as her Lord and Savior at Olivet Baptist Church in Chicago, IL.  Sometime later she converted to Catholicism, and then spent her last few years as a Born-Again believer and member of Family Life Centre (formerly Holding Forth the Word of Christ Church).

Mercedes was preceded in death by her father, Larney Nichols; mother, Gladys Kirk; brother Larney Nichols II and husband, Leroy (Buddy) Davis. Survived by sister, Gwen Wilson; daughters Phyllis Davis, Lenore Lewis, Beverly McBrayer (Edward), Barbara Carey (Welton) and Lolita Thomas (Melvin); sons Lawrence and Randall Davis (Pam); grand-daughters Shaquila Harris, Myesha Lewis, Tyann Sorrell (Clifton), Zofeyah McBrayer, Elisa Johnson (Tarl), Shadina Kibble, Shayla Davis, Jasmine Carey and Brianna Carey; grandsons Reondo Davis, Joseph McCloney Jr. (Brittany), Benjamin Harris, Jarrod Davis, Kendall Davis, and Welton Carey Jr. Mercedes is also survived by thirteen great-grandchildren, one great-great grand-daughter and a host of nieces, nephews and friends