1a.  Marriage Index:  Maryland, 1655-1850.  Liahona Research, Orem, UT (Broderbund CD-224):

Turner, Thomas

Corbin, Delia

Oct 24, 1797

Harford Co.

1b.  Robert Barnes.  1978/93.  Maryland Marriages, 1778-1800.  Genealogical Publ. Co., Baltimore, MD (Broderbund CD-195).

p. ix	BALTIMORE COUNTY... 12 BA - Marriage Register of Rev. John Allen, Rector of St. Johns Parish, 1796-1815, at HR [Hall of Records, Annapolis, MD].
p. xiv	HARFORD COUNTY... 3 HA - Marriage Licenses at Harford County Court House, Bel Air, transcribed by the author.  Marriages in the first part of the register may have actually taken place a year earlier than that indicated in the copy of the marriage license book available to the public.  Marriages listed as occurring starting in March 1791 probably have the correct date.
p. 233	Turner, Thomas, 24 Oct. 1797, Delia Corbin 3 HA-26; 12 BA-370 gives the date as 2 Dec. 1798

2.  1800 Census Index and Digital Images (online at Ancestry.com; Image #5 of 12; extracted by Diana Gale Matthiesen):

1800

MD

Harford Co.

District 1

p. 8

Thomas Turner

00111-10101-00

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	16-25	1774-1784	= Thomas's brother?
1 male	26-44	1755-1774	= Thomas
1 male	45 or over	in or bef. 1755	= Thomas's father?
1 female	9 or under	1790-1800	= Daughter
1 female	16-25	1774-1784	= Delia
1 female	45 or over	in or bef. 1755	= Thomas's mother?

This record is difficult to interpret without knowing more about our subjects.  I'm just guessing.  The elder couple is not Delia's parents as they are recorded in their own household.  It may even be that this record is not our subjects, at all.