Don't have sufficient proof but I believe Mary Ann was a daughter of Thomas Mattingly, Jr. and his wife Maria.Thomas is on the 1870 census of DC as follows:
Thomas Mattingly 44 born Virginia Maria33 born DC Malinda 13 born DC Mary A.10 born DC Josephine7born DC Barbara E.2born DC
Beyond this, we have the 1850 DC census
Thomas Mattingly 76born Virginia Jane63born Virginia Thomas 22born Virginia Lewis Payne22 born DC (son in law likely) Mary Ann Payne 21born Virginia Mary Jane Payne1 born DC
I have not connected Thomas Mattingly, Sr. to a family lineage as yet.It is possile that he was a son of Orlando Mattingly and his first wife, Annie Hough.This couple were also from Virginia and relocated to DC.Orlando's second wife was Anna M. Skirving.