I had to type what I heard and I wrote orra. It is generally accepted that it is not possible to distinguish these reliably - certainly I do not know the difference, and it is definitely impossible when you are not familiar with the way the speaker pronounces different words. That makes this an impossible question in the absence of context. If it had been something singular, we would no it was 'she' but 'she' or 'they' could have gloves on.
Did you report it? I think (not sure though) that contributors can exempt this sentence from listening exercises (or add they among the accepted answer?). I think oirre and orra are (or at least might be) both pronounced the same, as /oRə/ (but I cannot quickly find any reliable source transcribing them).
Yes I did. I have heard it stated by experts that you cannot tell the difference. I know of no modern dictionary that is reliable for pronunciation or that has pronunciation for inflected forms. Neither even seems to be in SGDS (Survey of the Gaelic Dialects of Scotland) either.
An obvious exception is that in traditional Lewis dialects there is a big difference between broad and slender r. But I infer from what Joanne says that this distinctive slender r may have spread to broad r, in which case it does not help, as well as spreading beyond Lewis to a larger part of the Western Isles.