Genoese...Bolognese... Sicilian...ravenna...Paduan...etc. those terms make sense when describing those inhabiting these regions/City states of the Italian peninusla in that time.
Most “journalists” don’t know these things.
But once again gently...Saint Rosa is a Christian saint born in Vitervo. Describing her “Italian” makes almost as much sense as calling Saint Nicholas a Turk (gasp). Ethnicity makes little sense when discussing Christinity.
I would say, from the vantage point of the same fact that Italy was not a nation state till 19c, — that you two should not bring the modern assumption about ethnicity needing a state in to medieval contexts.
“Italian” means as much and as little as “Greek”, “English” or “French”. It identifies the country (not the state) of birth, the native language, physiognomy, etc. It has nothing to do with political structures.
It is not the same as describing a Byzantine bishop as a “Turk” because the Turks did not settle in Asia Minor till centuries later.
It would be nice — although a tad pedantic — to identify St. Rosa with greater precision (as what, Lazian?) but it is not necessary. There si nothign wrong with the adentification int he article. Again, the adjective “Italian” as we just saw, existed since at least 1c.