1.  Jordan R. Dodd, ed.  1993.  Kentucky Marriages: Early to 1850.  Liahona Research, Orem, UT (Broderbund CD-229):

Hall, Robert	Pyle, Sarah	Mar 25, 1812	Christian Co.
Hall, Robert	Mccord, Mary	Nov 23, 1837	Christian Co.

2.  LDS.  Family Search: Internet Genealogy Service:  IGI - International Genealogical Index (online at FamilySearch.org).

Nancy E. HALL Birth: 18 Jul 1827, Hopkinsville, Christian, Kentucky Father: Robert HALL; Mother: Sarah PYLE Source: patron submission

3a.  Census Index:  U.S. Selected Counties, 1820 (Broderbund CD-314):

1820

Hall, Robert

KY

Christian Co.

p. 33

3b.  Christian County Genealogical Society (Hopkinsville, KY).  1995.  Christian County, KY, Census Records, 1820-1830-1840.  Simmons Historical Publ., Melber, KY.  On p. 7 (of the book, not the census):

1820

Hall

Robert

000010-30010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	26-44	1775-1794	= Robert (b. 1782/3)
3 females	9 or under	1810-1820	= Daughter C = Daughter B = Daughter A
1 female	26-44	1775-1794	= Sarah

4a.  Census Index:  U.S. Selected Counties, 1830 (Broderbund CD-315):

1830

Hall, Robert

KY

Christian Co.

p. 35

4b.  Christian County Genealogical Society (Hopkinsville, KY).  1995.  Christian County, KY, Census Records, 1820-1830-1840.  Simmons Historical Publ., Melber, KY.  On p. 44 (of the book, not the census):

1830

Hall

Robert

100 100 100 - 201 201 000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1825-1830	= Son? B
0 males	5-9	1820-25	= Elihu (b. 1822/3)
1 male	15-19	1810-1815	= Son? A
1 male	40-49	1780-1790	= Robert (b. 1782/3)
2 females	4 or under	1825-1830	= Daughter D = Nancy (b. 1827)
1 female	10-14	1815-1820	= Daughter C
2 females	15-19	1810-1815	= Daughter B = Daughter A
1 female	30-39	1790-1800	= Sarah

The teen-age boy is not their son because he did not show up in 1820, unless the census-taker made an error in 1820 or unless it's Elihu, tallied in the wrong column, because, otherwise, Elihu is missing.

5a.  Census Index:  U.S. Selected Counties, 1840 (Broderbund CD-316):

1840

Hall, Robert

KY

Christian Co.

p. 226

5b.  Christian County Genealogical Society (Hopkinsville, KY).  1995.  Christian County, KY, Census Records, 1820-1830-1840.  Simmons Historical Publ., Melber, KY.  On p. 81 (of the book, not the census):

1840

Hall

Robert

000 100 010 - 002 110 100

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	15-19	1820-1825	= Elihu (b. 1822/3)
1 male	50-59	1780-1790	= Robert (b. 1782/3)
2 females	10-14	1825-1830	= Daughter D = Nancy (b. 1827)
1 female	15-19	1820-1825	= Daughter C
1 female	20-29	1810-1820	= Margaret (b. 1819/20)
1 female	40-49	1790-1800	= Mary

Margaret appears to be Mary's daughter by her first husband.

6.  1850 Census Index/Images (online at Ancestry.com; Image #134 of 137):  District No. 1, Christian Co., KY, p. 496B, enumerated 18 Oct 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

946	1611	Robert Hall	67	M	Farmer	400	Ten
		Mary Hall	54	F			NC
		Nancy Hall	23	F			Ky
		A? Hall	11	F			Ky
		John Keys	9	M			Ky
	1612	Elihu F Hall	27	M	Farmer		Ky
		Sarah J Hall	27	F			Ky
		Margaret McCord	30	F			Ky

"A? HALL" was not with them in the 1840 Census.  Is this enumerator error?  Or is A. HALL a grandchild of Robert's?  And who is John KEYS?  Sarah is Elihu's wife.  Margaret McCORD appears to be an unmarried daughter from Mary's first marriage.