1.  Marriage Record:

2.  1830 Census Index/Images (online at Ancestry.com):  can't find.

4.  1840 Census Index/Images (online at Ancestry.com; Image #35 of 38; extracted by Diana Gale Matthiesen):¤•

1840

PA

Philadelphia Co.

Blockley Twp.

Roll 489

p. 176B

Ln. 18

Dr. Wm. Gallager

111 001 - 010 120

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1835-1840	= William (b. 1836/7)
1 male	5-9	1830-1835	= Samuel (b. 1833/4)
1 male	10-14	1825-1830	= Stephen
1 male	30-39	1800-1810	= William (b. 1804/5)
1 female	5-9	1830-1835	= Sarah (b. 1832/3)
1 female	15-19	1820-1825	= ?
2 females	20-29	1810-1820	= Mary Ann (b. 1807) = Sarah (b. 1808/9)

Are Mary and Sarah both fibbing about their age already?

5.  1850 Census Index/Images (online at Ancestry.com; Image #117 of 135):  West Philadelphia, Philadelphia Co., PA, p. 558A, 827/866, enumerated 16 Sep 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

William Gallager	45	M		Physician	7000	Pa
Mary Ann    "	39	F				"
Sarah E     "	17	F				"
Samuel      "	16	M				"
William     "	13	M				"
Julia Boyle	30	F				Ireland
Sarah E Capp	41	F				Pa
William Boyd	15	M				"

6.  George Norbury MacKenzie, ed.  1907.  Colonial Families of the United States of America.  Grafton Publishers, New York (reprinted 1966 by Genealogical Publishing Co., Baltimore, MD; OCR'd version online at Ancestry.com).  On pp. 132-137:  a genealogy of Seth Bunker CUPP, grandson of Mary Ann's brother, John Charles CAPP.