Here is the very odd listing for Sarah's marriage from the State of Illinois database. It appears to be confused with someone elses.
HOWE, NICHOLAS W., GASAWAY, SARAH , SANGAMON 08/23/1876 5/ 108
SHORES, JAMES, GASAWAY, SARAH, SANGAMON 08/23/1876 5/ 108


All marriages for Sarah Gasaway in the IL index..
HOWE, NICHOLAS W GASAWAY, SARAH SANGAMON 08/23/1876 005/0108
SHORES, JAMES GASAWAY, SARAH SANGAMON 08/23/1876 005/0108
SMITH, JOSEPH GASAWAY, SARAH WILLIAMSON 05/12/1841 A /10
TREFT, WILLIAM GASAWAY, SARAH M LOGAN 08/27/1868 002/0050 00002065
MANN, MICHAEL J GASAWAY, SARAH V LOGAN 02/10/1870 002/0077 00002416

With 2 “S”s
WEST, JOHN M GASSAWAY, SARAH E MC LEAN 02/27/1876 OOH/0019