Both names Anna & Rosina are Most DEFINITELY Italian! Columbian - or any Hispanic name - would have "ita" @ the end... Italian names & diminutives have ina/ino or etta/etto (ex: Antonietta, etc.). I am of Italian origins & have lived there for 15 yrs. I also went to school there while on my stay & I teach both Italian & Spanish. Hope this sheds some light on your doubts. However, "Decker" is obviously Not an Italian name... Italian names always end in a vowel & there is no letter j, k, w, x, nor y in the Italian alphabet. Good luck with your research.