Emma, What a great find! I looked on the census for 1861 and I found that Robert Roberts and Margaret Roberts were in the Poor House. I could not find anything after that but your find shows that he maybe died in there. Don't know about Margaret though.
There is nothing to see about children and how many they had. Will check out the Archives for those. Great to know the 1st wife's name. Could be more for the tree!
Just one more bit of info about Robert Roberts born 1867, the son of Edward and Margaret, Edward(born 1840) son of Elias (born 1819).
As well as daughter Maggie (born 1900), they had two more daughters,Anne born 1903 and Gwyneth born 1907. They all lived at Efail y Waen Glanwydden, there is a connection with the Williams family who was the blacksmith. I think Roberts wife, down as Mary E Roberts, was the daughter of the Williams family. On the 1901 census Robert is listed as son in law. One of the Williams boys was Robert B Williams born 1895. I saw there was a memorial inside the Ainon Welsh Baptist Chapel for the 1st world war. The names listed as soldiers were:
Goronwy Evans Wiga
Thomas K Jones Tan y Bryniau
Robert Roberts Bryn Bach
Robert B Williams Efail y Waen
Don't know if the Roberts was one of ours. I think I have found most of what I can using the Census. I will keep digging, you never know what turns up!