Nativitas est hodie sanctæ Mariæ Virginis, cujus vita inclyta cunctas illustrat ecclesias.
Today is the Nativity of Saint Mary the Virgin, whose renowned life enlighteneth all the churches.
I suspect very strongly that there is a Greek original for at least the second antiphon at Lauds of the Feast of the Nativity of Our Lady – why? because it ends cujus vita inclyta cunctas illustrat ecclesias, "whose renowned life enlighteneth all the churches": and to speak of churches in the plural is typically Greek, whereas the Latin West much prefers to speak of the Ecclesia in the singular. (Note also that this phrase is also employed as the repetend for the 4th Matins Responsory.)
Similarly, the word hodie employed in the opening phrase is a dead giveaway, since many Latin anthems beginning Hodie are from Greek anthems beginning Σημερον, as I noted on this blog long ago. (Very significantly, the 1st Matins Responsory begins with Hodie, and thus may very well also derive from a Greek original.)
Furthermore, that word inclyta, from in- plus clueo (itself cognate with Greek κλύω, meaning amongst other things to be called or named), signifying being renowned, that is, called great – yclept great, to use the ancient past tense revived by horrid Milton, which sounds so similar – savours somewhat of Greek to me, if only by its spelling...
Whatever of that, I do think that this antiphon at least may stem from Greek, since this Feast first arose in the East, and very often very old non-Scriptural antiphons and the like were taken from Greek anthems (as the Epiphany antiphons were, and as the Magnificat antiphon for this very Feast, as noted in an earlier post, derives from the Greek Troparion therefor).
Unfortunately, not having a copy of The Festal Menaion, I cannot access the Canon and other Byzantine liturgical texts for this day, so I cannot try and confirm this theory.