There are only two families in Montour County with the possibility of being Leah's parents (both have unaccounted-for daughters Leah's age).  Based on proximity and other factors, these are the most likely parents for Leah:
Father possibly:  Joseph STRAUB
Mother possibly:  Barbara __?__

The other potential couple is:  (Johann) Adam STRAUB & (Maria) Catharina HEILMAN

(Leah appears to have shaved a few years off her age along the way, so her tombstone gives a later birthyear than was probably true.)

Said to have this son, but he does not occur with our subjects in any census.
.  Elijah WERTMAN, b. 1835/6 or 1833; d. 1906

1.  Marriage Record:

2.  1830 Census Index/Images (online at Ancestry.com; Image #9 of 20; extracted by Diana Gale Matthiesen):¤•

1830

PA

Columbia [now Montour] Co.

Mahoning Twp.

p. 56

Ln. 25

George Wertman

200 001 - 000 010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 males	4 or under	1825-1830	= Emmanuel (b. 1827/8) = Son A
1 male	30-39	1790-1800	= George (b. 1800)
1 female	20-29	1800-1810	= Leah (b. 1804/5)

Listed next to John WERTMAN (æ 40-50).

3.  1840 Census Index/Images (online at Ancestry.com, Image #9-10 of 12; extracted by Diana Gale Matthiesen):¤•

1840

PA

Columbia Co.

Montour Twp.

pp. 230B-231A

Ln. 10

George Wortman

211 001 - 101 010

0001000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 males	4 or under	1835-1840	= John (b. 1839/40) = William (b. 1835/6)
1 male	5-9	1830-1835	= Amos (b. 1834/5)
1 male	10-14	1825-1830	= Emmanuel (b. 1827/8)
1 male	30-39	1800-1810	= George (b. 1800)
1 female	4 or under	1835-1840	= Caroline (b. 1837/8)
1 female	10-14	1825-1830	= Abby (b. 1831/2)
1 female	20-29	1810-1820	= Leah (b. 1804/5)
1	person employed in manufacture and trade

Listed next to John WORTMAN (æ 30-40).

4.  1850 Census Index/Images (online at Ancestry.com; Image #2 of 8):  Cooper Twp., Montour Co., PA, p. 379B, 11/11, enumerated 16 Sep 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

Geo Wertman	49	M		Labourer		Pa
Leah Wertman	45	F				"
Abby Wirtman	18	F				"
Enos Wertman	15	M		Boatman		"
Wm Wertman	14	M				"
John Wertman	10	M				"
Caroline Wertman	12	F				"
Joseph Wertman	5	M				"
Daniel Wertman	3	M				"
Barbara Wertman	3/12	F				"
Emanuel Wertman	22	M		Shoemaker		"

Listed next to John WERTMAN (æ 33, b. PA, wife Mary).  I've no explanation why Emmanuel was listed last.  Ususally that means the person is not a son of the householders, but there is a male Emmanuel's age in the household in the 1820 and 1830 censuses, and he is said to be their son.

5.  1860 Census Index/Images (online at Genealogy.com, Image #1 of 19):  Danville P.O., Mahoning Twp., Montour Co., PA, Roll 1146 (Book 1), p. 271A, PN 99, 703/703, enumerated 20 Jun 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):¤•

Amos Wertman	23	M		Day Laborer			Pa
Leah	57	F					"
William	21	M		Day Laborer			"
Joseph	16	M					"

6.  1870 Census Index/Images (online at Genealogy.com, Image #18 of 37):  Danville P.O., Borough of Danville (Ward 2), Montour Co., PA, p. 106B, PN 18, 136/145, enumerated 24 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):¤•

Wortman Leah	62	F	W	Keeping House			Pa
_______ Amos	32	M	W	Laborer			"
_______ William	30	M	W	"	1200	100	"
_______ Caroline	25	F	W	Tailoress			"

Also in Danville (Ward 2): Elijah WORTMAN (æ 34, b. PA, wife Lavinia; Img#15 of 37, p. 105A, 110/119).

8.  Emails from Tom Young, descendant of our subjects.