The Romans

pueblo wrote: »

For the amateurs among us can you spell out what this means? Are these looking like Roman style burials?

There is no definitive, or readily identifiable Roman burial practice. Cremation was the norm in the early days of the empire - primarily amongst the well heeled. Flexed or extended burials followed and then there was something of a return to crouched burial in the late 4th and early 5th centuries.
This potted chronology would hold true if one region was in focus. The problem is, we don't really know what region we are dealing with, so we don't know what the 'standard practice' was. Are we dealing with residents or visitors? Where did they come from and why did they come to Ireland? Those are the principal questions and we won't be able to answer them based on the morphology of the graves alone.
We can't say that the style of burial is an indication of Roman identity. We can't say that it's not.
All we can say at this point, is that we have two markedly different burials in a later Iron Age cemetery and that this also happens to coincide with the latter days of the Roman empire. Based on the isotope analysis, the inhumed bodies do not appear to have been born in Ireland. Putting those two tenuous facts together is not grounds for assuming the burials are Roman.
Further investigations are definitely needed. Perhaps, as Dubhtach says, DNA might give us a better picture.
The stone on the woman's* abdomen is not a characteristically Roman practice, as far as I can gather, but it sure is curious.

*the adult burial may not be a woman, or so I've been told. Many of the potentially Roman finds dismissed down through the years, are being revisited.

Here is an outline of the finds from Drumanagh, together with a summary of the LIARI research findings to date.
http://www.archaeology.co.uk/articles/features/worlds-apart.htm