Hi Vilma, I have been looking at the BMD for NSW in that period, I Have a marriage for Charles and Elizabethin 1843. I also can find no death for Charles before 1851.
Strangely I have children born to them from 1844 Charles,1847 Mary,1850 Charles, 1853 George and 1862 Elizabeth. Elizabeth appears to have died in 1864.
I believe you have two possibilities they married outside NSW, second you have the wrong Elizabeth Returned in 1851 census. I could also have listed other Jones children with same parent names, Jones is an extremely difficult name to trace.
Neil