Secondary sources give Mary these parents, but where's the evidence?
Father:  Peter CARRICO
Mother:  Nancy WILKERSON

Some secondary sources consider Elizabeth to be their daughter, but I'm not convinced.
2.  Elizabeth Valentine FADDIS, b. 1840/1

1.  Marriage Record:

2a.  1840 Census Index/Images (online at Ancestry.com):  the Grayson Co., VA, page images are missing and are not indexed.

2b.  Census Index:  U.S. Selected Counties, 1840 (Broderbund CD-316):

1840

VA

Grayson Co.

Eastern Dist.

p. 276

Fadis, Andrew

2c.  1840 Census Images (online at Genealogy.com, Image #7 of 54; extracted by Diana Gale Matthiesen):¤•

1840

VA

Grayson Co.

Eastern Dist.

Roll 556 (Book 1)

p. 276

Ln. 12

Andrew Fadis

100 010 - 000 001

no slaves

0100000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1835-1840	= William (b. 1836)
1 male	20-29	1810-1820	= Andrew (b. 1809)
1 female	30-39	1800-1810	= Mary (b. 1810)
1	person employed in agriculture

3.  1850 Census Every-Name-Index/Images (online at Ancestry.com, Image #102 of 130):  11th Dist., Carroll Co., VA, Roll M432_939, p. 369A, 761/761, enumerated 11 Oct 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

Andrew Faddis	41	M		farmer	500	NC
Mary      "	42	F				Va
William   "	14	M				Va
Elizabeth Valentine	9	F				Va

Secondary sources say she's their daughter, but there's no indication in this census record that her surname is FADDIS.

4.  1860 Census Every-Name-Index/Images (online at Ancestry.com, Image #113 of 197):  Hillsville P.O., Carroll Co., VA, Roll M653_1339, p. 877, PN 111, 723/728, enumerated 2 Aug 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):¤•

Andrew Faddis	51	M		Farmer	2000	700	N Carolina
Mary     "	51	F					Virginia

5.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #26 of 41):  Hillsville P.O., Piper's Gap Twp., Carroll Co., VA, Roll M593_1639, p. 489B, PN 26, 170/175, enumerated 19 Aug 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

Faddis Andrew	62	M	W	Farmer	$720	$1076	Va
______ Mary	52	F	W	Keeping House			Va
______ Caroline	19	F	W	At Home			Va
Carrico Caroline	79	F	W	At Home			Va

If Caroline FADDIS is their daughter, where was she in 1860?  If Caroline CARRICO is Mary's mother, we've got Mary connected to the wrong parents.  Unfortunately, I can't find either Caroline in 1860, nor the elder Caroline in 1850.

6a.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #51-52 of 55):  Piper's Gap Dist., Carroll Co., VA, Roll T9_1360, pp. 107D-108A, PN 52-53, SD 5, ED 20, enumerated 25 Jun 1880, official enumeration date 1 Jun 1880 (extracted by Diana Gale Matthiesen):•

1880:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).

1

2

3

4

5

6

7

8

9

10

11

13

14

24

25

26

476

476

Faddis Andrew

W

M

71

/

Farmer

NC

NC

NC

Williams Jesse

W

M

25

Servant

/

Works on farm

2

Va

Va

NC

[next page]

________ Callander

W

F

24

Servant

Keeping house

Va

NC

Va

________ Emma

W

F

9/12

Oct

/

Va

Va

Va

6b.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #53 of 55):  Piper's Gap Dist., Carroll Co., VA, Roll T9_1360, p. 108B, PN 54, SD 5, ED 20, enumerated 26 Jun 1880, official enumeration date 1 Jun 1880 (extracted by Diana Gale Matthiesen):-

1880:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).

1

2

3

4

5

6

7

8

9

10

13

22

23

24

25

26

490

490

Edwards Orvell

W

M

25

/

Farmer

Va

Va

Va

_______ Margaret

W

F

26

Wife

/

Keeping House

/

/

NC

NC

NC

_______ Swift

W

M

4

Son

/

Va

Va

NC

_______ Lavora

W

F

11/12

July

Dau

/

Va

Va

NC

Faddis Rebecca

W

F

60

Mother

/

Va

Va

Va

7.  1890 Census:  the 1890 Census Population Schedules were destroyed.