Do you know where she died in Illinois? Do you know when George Jones was born?
Could this be them:
1910 Census La Prairie Township, Marshall County, Illinois
George Jones, 68, married 1 for 38 years, born in England, parents also, arrived 1873, naturalized, farmer, general farm, he rented the farm but worked on his own account
Mary Jones, 74, married 2x, this time for 38 years, 12 children, 10 alive, born in England, parents also, no arrival date,
https://www.familysearch.org/ark:/61903/1:1:MK6L-LS3---
Do you have the names and birth years for Mary's children by John Wilson? Finding them in the US might help you find Mary. Or do you know what part of the US they lived in? Illinois also?