There's some discussion here on Greek names honoring Isis
, at Oxford's Lexicon of Greek Personal Names site:http://www.lgpn.ox.ac.uk/names/meaning.htmlIsis
worship became quite widespread among the Greeks and Romans both; you can visit a temple of Isis
at Pompeii, for instance. It's also important to remember that as a result of Alexander
the Great's conquests, and the subsequent Ptolemaic (Macedonian and Greek) dynasty in Egypt, there was a lot of cultural fusion going on. Egypt was full of Greek speakers, and Isidoros/Isidora are very well-represented names in documents from the Greco-Roman period.