Question

Issue with Sarah Lankford born 1763 after her father's death 1757?

Answer 1

Here are a couple of sources for Sarah - her marriage record:

"North Carolina, County Marriages, 1762-1979 ," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:F8FH-1LV : 22 December 2016), Parrish Lanford and Sarah Lorrane, 07 Jan 1783; citing , Granville, North Carolina, United States, p. 107, North Carolina State Archives Division of Archives and History; FHL microfilm 19,009. 

Parrish died in August, 1829 and Sarah and their son John were appointed administrators of his estate in Dickson, Tennessee: Register to Estate Settlements, 1800-1950; Author: Tennessee County Court (Dickson County); Probate Place: Dickson, Tennessee

https://www.ancestry.com/sharing/16743613?h=9b3fdf&utm_campaign=bandido-webparts&utm_source=post-share-modal&utm_medium=copy-url

Without seeing the will, it's not certain this is her father, but Ancestry has the following will abstract:

William Lawrence
Probate Year:1766
Estimated Death Year:Abt 1766
Inferred Place of Death:North Carolina, USA
Full Abstract:1766 LAWRENCE, WILLIAM, Deborah (wife); children (not named).

and a transcript of the will - which names no children - is at

www.ncgenweb.us/ncgranville/wills/early-granv-wills4.htm
 

Comments

I added sources to Sarah, corrected father's death date and added links to his will transcript

Answer 2

Simple answer is sources are needed for the family. Ancestry tree is all that is found for her father, mother, and herself, so there is no proof if she belongs to these parents or birth or death for anyone.