1.  Marriage Record:

2.  1830 Census Index and Digital Images (online at Ancestry.com; Image #15 of 16; extracted by Diana Gale Matthiesen):

1830

PA

Northampton Co.

Towamensing Twp.

p. 214

David Shafer

000 010 - 100 010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	20-29	1800-1810	= David (b. 1809/10)
1 female	4 or under	1825-1830	= Daughter A
1 female	20-29	1800-1810	= Eve (b. 1809/10)

Listed 12 lines from Dewaldt STRAUB, father of David STRAUB (see 1850). 

3.  1840 Census Index and Digital Images (online at Ancestry.com; Image #9-10 of 22; extracted by Diana Gale Matthiesen):

1840

PA

Northampton Co.

Towamensing Twp.

pp. 252B-253A

Dav: Shafer

110 001 000 - 020 001 001

0100000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1835-1840	= Son B
1 male	5-9	1830-1835	= Son A
1 male	30-39	1800-1810	= David (b. 1809/10)
2 females	5-9	1830-1835	= Daughter B = Mary (b. 1831/2)
1 female	30-39	1800-1810	= Eve (b. 1809/10)
1 female	60-69	1770-1780	= mother? mother-in-law?
1	persons engaged in agriculture

4.  1850 Census Index/Images (online at Ancestry.com; Image #21 of 29):  Lower Towamensing Twp., Carbon Co., PA, p. 289A, 132/137, enumerated 26 Aug 1850 (extracted by Diana Gale Matthiesen):

David Shafer	40	M		Farmer	500	Pennsylvania
Eve	40	F				"
Mary	18	F				"
Elizabeth	9	F				"

Living two doors from David & Mary (OLEWINE) STRAUB. 

5.  Census Index:  U.S. Selected Counties, 1860 (Broderbund CD-318):  can't find, and Carbon Co., PA, records are indexed on the CD.

6.  1870 Census Images (online at Ancestry.com; Image #8 of 40):  Parryville P.O., Lower Towamensing Twp., Carbon Co., PA, p. 148B, PN 8, 50/55, enumerated 30 Jul 1870 (extracted by Diana Gale Matthiesen):

Shafer David	60	M	W	Carpenter	3500	100	Penna
______ Eve	60	F	W	Keeping House			"
Stroub Samuel	30	M	W	Works in Furnace			"
______ Elizabeth	28	F	W				"
______ Julia	14	F	W				"