There are a few issues with George and Maryette being the parents of William
Issue 1 - Mary was born in 1839 and William was born in 1852 - making her just 13 when he was born
Issue 2 - George and Maryette married in 1858 (6 years after William was born) and started having children from 1859
Issue 3 - William does not appear in the 1860 census with George and Maryette (he would have been 8)
Issue 4 - William does not appear in the 1870 census with George and Maryette (he would have been18)
Issue 5 - William does not appear in the 1875 census with George and Maryette (he would have been 23)
Issue 6 - George's obituary published in the Watkins Express on 27 July 1921 states he is survived by a wife, 3 daughters (Mrs Fred Roe, Mrs Alice Crout, Mrs Deane Crout) and 5 sons (Clarence, Oscar, Neil, Orner and Minor). William did not die till 1939 therefore if he was a son he should have been listed
Issue 7 - William appears in the 1855 census with Stephen and Elizabeth (aged 3)
Issue 8 - William appears in the 1860 census with Stephen and Elizabeth (aged 8)
Each of these sources are shown on the profiles.