Possibly:
.  (Son) KAPP, b. ca. 1810s; d. 1840s; m. Sarah __?__ 

1.  F. Edward Wright.  1995.  Early Church Records of Lebanon County Pennsylvania.  Family Line Publ., Westminster, MD (Broderbund CD-166).

TRINITY TULPEHOCKEN CHURCH...

May 27, 1798 John Kapp and Magdalene Dieffenbach.

Elizabeth of John Kapp and Magdalene, b. Mar 10, 1799; bapt. May 31, 1799. Spon: William Hendel and Margaret.

2.  1800 Census Index/Images (online at Ancestry.com; Image #1 of 3; extracted by Diana Gale Matthiesen):

1800

PA

Dauphin [now Lebanon] Co.

Heidelberg Twp.

Schaefferstown

p. 223

Ln. 22

John Kapp

00010-10110-00

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	26-44	1755-1774	= John
1 female	9 or under	1790-1800	= Elizabeth (b. 1799)
1 female	16-25	1774-1784	= ?
1 female	26-44	1755-1774	= Magdalene (b. 1774/5)

3.  1810

4.  1820

5.  1830

6.  1840

5.  1850 Census Index/Images (online at Ancestry.com; Image #5 of 14):  Schaefferstown, Heidelberg Dist. (Twp.), Lebanon Co., PA, p. 22A, 296/318, enumerated 3 Sep 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):¤•

John Heterich	56	M		Turner	800	Pennsylvania
Catharine "	49	F				"
Sarah Kapp	25	F				"
Adeline  "	6	F				"
Magdalena "	75	F				"

This Magdalena may not be our subject, but our subject is the only KAPP wife named Magdalena old enough that I know to have been in Lebanon County.  Catharine may be Magdalena's daughter, and Sarah could be Magdalena's widowed granddaughter-in-law.