Here is some information about Mary and her family.

Based on this information, she must have married sometime between 1880 and 1900. Since her father was indicated as owning property on earlier censuses and her mother was still living in 1880, a search for estate records for her mother might reveal Mary's first married name.

1837-8 - William Jackson, Sr. - will dated 17 Jan 1837, probated 5 Feb 1838 - Sary E Forest is in the list of heirs.

1840 SC Greenville Dist
Prince Forester 0-1-0-0-0-1 / 1-1-0-0-0-0-1 The ages on this listing match the listing in 1860.

1850 No Prince Forester or Forest found on index

1860 SC Greenville pg 347B Chincapin Division PO Mush Creek 9th Sept
Line 34 H1063/F944 Prince Forester 59 farmer $500/460 b SC [indexed on ancestry.com as Paince]
Sarah 62 housekeeper b SC
Elias 24 farmer b SC
Mary Frances 23 b SC
[James Jackson 66, Mary 71, Leanna 46 are listed as the family just before them.]

1870 SC Greenville pg 673A, 13 Hyland Township, PO Mush Creek 28th July
Line 10 H43/F43 Forest, H P 69 farmer $100/200 b SC
Sarah 70 b SC
Mary F 31 b SC [indexed on ancestry.com as May F]

1880 SC Greenville pg Highland Township 12th June
Line 19 H 202/F308 Forest, Mary 38 single, keeping house b SC/SC/VA
Sallie 83 widow, at home b VA/VA/VA

1900 No Mary Forest or Forester found on index