I'm not related. Just for clarification the people I found were Afro-American.
The 1930 census of Kinards, Greenwood Co., SC lists this family:
Lila Jackson 58 Lucile 18 Mamie L. Adams 14 (granddaughter) Lillie P. Adams 13 (granddaughter)
The 1920 census of Ninety-Six, Greenwood Co., SC lists this family:
Edward Adams 27 Julia 19 Mamie 5 Perfect 2 11/12
Under SC deaths is a Julia Adams who died May 6, 1922 in Greenwood County at age 18. She was the daughter Jno. Anthony and Susan Halloway.
John and Susan lived in Fellowship, Greenwood County. He died in 1937 and she in 1954 according to their SC death certificates.
From here things seem to get complicated and even strange.
The 1930 census of Pickins, Pinkins Co., SC includes a J. Edward Adams 38, Julia 30 and Edward Jr 8. I tried to find Edward in the 1910 and 1900 census, but without luck.
I tried to find data on Lila Jackson too also without luck. I did find an Eliza Jackson, wife of Thomas in the 1920, 1910 and 1900 censuses of Kinards which seem to fit. The 1920 census even includes a Mamie L. Jackson 6 listed as their granddaughter.
Some of these records you can look at for free at beta.familysearch.org and Ancestry.com. For those you cannot see for free I suggest checking with your local libraries to see if they have Ancestry or Heritage Quest.
Frankly, I don't know what the story is. Did Edward remarry to another Julia? Is the Julia who died in 1922 Mamie's mother or was she another Julia Adams? Was your Mamie related to the Jackson Family at all?
Unfortunately SC did not start having birth certificates until 1915. There may or may not have been county or other local birth records kept. I suggest getting her obituary and if you are related her death certificate. These should have data on her parents. Her marriage may also as might her Social Security application.