Simeon & Eliza were married circa: 1836-39 Eliza would have been 20 and that is 3 years before their first child Sarah was born.

1850 census: Morris Twnshp, Greene Pennsylvania
HEAD: Simeon Hathaway age 56 B: PA
Eliza 33 B: New Jersey
children:
Sarah age 11 (married a Hilton)
Alexander age 9 (married Matilda)
Mary age 7 (married Russell Puntenney)
Jesse age 5
Cinthia age 3 (Cynthia R Paterson-D: 12 Dec. 1826 Il)
Ebenezeer age 0 (3/12) married after 1870 census

1860 census Morris Twnshp, Greene Pennsylvania
HEAD: Simeon Hathaway age 67 B: PA
Eliza 45 B: New Jersey
Mary age 17
Alex age 15
Jepe (Jesse) age 13
Martha age 11 (born after the Oct 29 1850 census)
Ebine age 9
Stephen age 7

1870 census Dix, Ford Cnty. Illinois
HEAD: Alex Hathaway age 28 B: penn FARMER
Mary Hathaway age 27 B: Penn Keeping house
Eliza " age 54 B: New Jersey
Ebon G " age 20 works on farm
and a hand Dilly Leonard

1880 census Eliza is living with her daughter, Mary and son-in-law Russel Puntenney in Gibson Cy Illinois.
Simeon Hathaway's grave is NOT found. we know he died after the 1860 census was taken and before the July 15 1870 census was taken.

sources: 1850/60/70 census for Morris, Greene Pennsylvania
Mary, their daughter's death cert gives parents as:
Simeon Hathaway and Eliza Stillwell
the birth date is from the FAMILY BIBLE OF RICHARD AND ABIGAIL HATHAWAY I found on ancestry.com but sadly what TREE it actually came from did not print, I hope my Cuz who had it on the site does not mind that I placed it here, if so please don't get mad, just ask me to take it off...