A couple of important points.
First, there was a census in Wexford (and all of Ireland) in 1891. Unfortunately, the underlying returns were pulped by the British during World War I. All that still exists are the compiled census statistics and reports.
Second, it can be tricky to find an illegitimate birth. It was relatively common to call such children by their supposed father's surname (if known), at least in Ireland. However, illegitimate children were legally fatherless, so the fathers surname does NOT appear on birth registrations, only the mother's. So, one could go through life known by one surname, but the birth registration would show a different surname. The alleged father's name often appears on Catholic baptismal records, but I have no idea if this is also true of CofI or other denominations.
