1.  Marriage Record:

2.  1890 Census:  the 1890 Population Schedules were destroyed.

3.  1900 Census Index/Images (online at Genealogy.com; Image #1 of 31):  Freeburg, Washington Twp., Snyder Co., PA, p. 249A, SN 1, SD 10, ED 183, enumerated 1 Jun 1900, official enumeration date 1 Jun 1900 (extracted by Diana Gale Matthiesen):¤•

1900:  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	12	13	14	15	17	19	21	22	23	24	25	27
7	7	Hinkle Jerry	Head	W	M	Nov 1858	41	M	10			PA	PA	PA	41	Day laborer		Y	Y	Y	R	H
		______ Malinda	Wife	W	F	Oct 1857	42	M	10	3	2	PA	PA	PA	42			Y	Y	Y
		______ Charles F	Son	W	M	July 1889	10	S				PA	PA	PA	10	At School	7	Y	Y	Y
		Stroub Sophia	Mother	W	F	Oct 1817	83	W		12	8	PA	PA	PA	83	Boarder		N	N	N

Sophia should have been listed as "Mother-in-Law."