There is some data that may partially reveal the "John and Ruth" family.
It starts with the 1851 census where there is a step-son John Ibal.
Ruth Rowland married Edward Ibal in 1815 and had children Robert(who died in infancy),John(1820),Sarah(1822),William(1824).I think these,with Sarah as Jane,are the first three children in the 1841 census(notorious for age inaccuracy even given the rounding).Edward dies in 1825.
A Ruth Ibal(widow) then marries a John Price in 1828,but I suspect he dies in 1830.
There is then a marriage of Ruth Rowland to a John Griffiths in 1836.(Perhaps she has reverted to her maiden name-I can only find one Ruth Rowland born in the area).There are two children born to John and Ruth Griffiths,Ann(1837),Thomas(1839).John is given s a collier from Argoed.This then matches the profile of the family in 1841,but why do they appear as Williams rather than Griffiths?
(I haven't yet checked to see if John Griffiths dies 1840 or 1841 and there is another marriage to John Williams!
Regards
Roger