jimf81 wrote:So that means Epifanio would have been born around 1815 and Petra around 1824?
Based on their ages in Ignazio's birth record, the answer to your question would be yes, but those are really only estimated years of birth. They may not be 100% accurate but it gives you something to go on for further research.
About that marriage record you found for Rosario. That record is dated Oct 3, 1868. In that record the father named Epifanio was deceased. In your Iganzio's 1878 marriage record, the father Epifanio was alive and living in the town. Also, as Marty pointed out, the mother Petra's surname was different, so I am inclined to agree with Marty that Rosario was not a sibling, unless these are errors in his marriage record.
Erudita