Kathy, no further findings on George and Mary Ann Green together with/without infant William.
Nothing below is a direct match, but MAYBE will be of use for the extended family??
Re: Pass Lists -- Only about 12 entries for Geo/Mary/Mary Ann Green in 1855-1856 however, not every ship's list is transcribed or may be only a portion is transcribed.
“Cosmo” Arr May 24, 1855 Glasgow to NY
George Green 34
Ezzel 33
Martha 11
Harriett 6
Elizabeth 4
John 3
“EC Scranton” Arr July 9, 1856 L’pool to NY
Geo Green 19 Farmer b. Eng Destination: Illinois
“Ross” Arr June 6, 1855 Departed fr, Hull to NY
Mary Ann Green 19 wife Destination Detroit
Timothy Green 24 Gardner Destination: Detroit
“Sam Dunning” Arr May 30, 1856 L’pool to NY
Thos Green 48 Lab
Mary Ann 42
Christopher 19
Patrick 11
Jno 8
Kate 5
1850 US Census Cass Co., IL
Everybody is surnamed Green, everybody b. in England
Joseph 62 Farmer
Mary A. 34 wife??
Aaron 18
Edwin 14
Charles 26
Anna 36
Martha A 1
1850US Census Town of Sparta Randolph Co., IL
Robert Gamble 32 b. in Scotland Miller
Jane A. 22 b. in Scotland
Robert J. 2 b. in IL
No hits for "Gambles" in IL in 1850
Maybe planned to immigrate but got homesick or for some other reason decided not to stay in US?
I'll look in 1860 US for Green and Gamble/Gambles and let you know.
kathy