Malachi Wall married Mary Ginnett (Jinette) in July 1849. A Mary Wall died May 1850 in Johnson. (age 27, married). You might try to to contact the Johnson Town Clerk to see if there is a death record with more information on an actual death certificate.
Marriage Record lists her father only as "Mac Wall''
Source: North Carolina, County Marriages, 1762-1979 ", database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:QKJQ-BMXP : accessed 16 May 2016), U L Johnson Crowder and Mary Wall, 1869
Image: https://familysearch.org/ark:/61903/3:1:3QS7-894J-11ZM?i=883&wc=QZM2-S3L%3A1588773185%2C1588773501%3Fcc%3D1726957&cc=1726957
Name U L Johnson Crowder
Father Isaiah Crowder Mother Betsey Crowder
Marriage 14 Jan 1869 Wake, North Carolina
Spouse Mary Wall
Father Mac Wall
Source: North Carolina, County Marriages, 1762-1979 ," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XF9V-GMC : accessed 16 May 2016), Malichi Wall and Mary Ginnet, 11 Jul 1849; citing Johnston, North Carolina, United States, county courthouses, North Carolina; FHL microfilm 546,460
Image: https://familysearch.org/ark:/61903/3:1:S3HT-6QZS-38V?mode=g&i=213&wc=QZM2-SRD%3A1588772759%2C1588772757%3Fcc%3D1726957&cc=1726957
Name Malichi Wall
Event Type Marriage License
Event Date 11 Jul 1849
Event Place Johnston, North Carolina, United States
Spouse's Name Mary Ginnet
United States Census (Mortality Schedule), 1850," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M3VP-RRV : accessed 16 May 2016), Mary Wall, Johnson county, Johnson, North Carolina, United States; citing line 24, NARA microfilm publication T655 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 2,155,598
Mortality Census 1850 Johnson county, Johnson, NC
Name Mary Wall
Female Age 27 Marital Married
Birth (Est) 1823 North Carolina
Death Date May 1850