This is interesting. I took a look on family search.org beta search for the Stephen Andrew Simmons born 1886 Utah. He came up in the 1900 USA census in Charleston county Wallsburg with his parents.
George C (transcribed as C but s/be E) Simmons age 72 gardener born England Jan 1828 parents English. married to present wife 25 years 11 children to this marriage 7 living.
Dora wife born in England April 1855 age 45 both parenjts English
John W born Nov 1880 Utah age 19
Maud B dau born Aug 1882 Utah age 17
Stephen Nov 1886 Utah age 13
Bertha M dau born March 1889 Utah
J William Simmons, grandson born Jan 1888 age 12 Utah.
George gives his year of immigration to the US as 1876 which is why I can't find them in 1881 uk. Now he says he and Dora have been married 25 years so that was 1875 so it was before going to US but it is not Dora born 1841 and married to George Simmons in Essex as this Dora in Utah was born in 1855. Another reason it can't be Dora born 1841 is because she was in England in 1881, 1891, 1901 and 1911.