I don't know if this helps or not. It's information on the Joseph and Sarah Jackson buried next to Mary. Joseph's mother's name was Mary but is it the same one you're looking for?
Collection: Louisiana Deaths, 1850-1875; 1894-1954 Name: Joseph Emil Jackson Death Date: 02 Apr 1945 Death Place: Westlake, , Calcasieu, Louisiana Gender: Male Race (original): W Race (standardized): White Age: 70 Estimated Birth Year: 1875 Birth Place: Vernon Parish, Louisiana Marital Status: Married Spouse's Name: Sarah Jackson Father's Name: Mother's Name: Mary E Gordy Film number: 1220970 Image Number: 00297 Certificate Number: 519973 Digital Folder Number: 4213518
Name: Sarah West Jackson Death Date: 06 Apr 1951 Death Place: Westlake, , Calcasieu, Louisiana Gender: Female Race (original): White Race (standardized): White Age: 72 Estimated Birth Year: 1879 Birth Place: Westlake, Louisiana Marital Status: Widowed Spouse's Name: Joseph E Jackson Father's Name: Absoloam Jackson Mother's Name: Martha Dewitt Film number: 1418607 Image Number: 01005 Certificate Number: 699 Digital Folder Number: 4215567
1930 United States Federal Census Police Jury Ward 4, Calcasieu Parish, Louisiana Joseph E. Jackson head m w 56 (md at 23) born LA fborn US mborn AL farmer Sarah O. Jackson wife f w 51 (md at 18) born LA fborn MS mborn MS
1910 United States Federal Census Precinct 3, Calcasieu Parish, Louisiana Joe E Jackson head m w 37 md born LA fborn LA mborn LA farming Sarah O Jackson wife f w 31 md1 2ch 2liv born LA fborn MS mborn MS Lillie Jackson dau f w 11 born LA fborn LA mborn LA Eva M Jackson dau f w 7 born LA fborn LA mborn LA
1900 United States Federal Census Police Jury Ward 4, Calcasieu, Louisiana Joseph E Jackson 27 head w m md 3yrs born Nov 1872 LA fborn SC mborn AL day laborer Sarah Jackson 21 wife w f 1ch 1liv born Sep 1878 LA fborn MS mborn MS Lilly Jackson 1 dau w f born Jun 1898 LA fborn LA mborn LA Mary Jackson 63 mother w f widow born Jun 1836 AL fborn SC mborn AL