About Marija Piantanida
After her husband died, Kata was left with 6 children. 3 of them were sent to their uncle Petar in Argentina. It looks like one of them went to USA.
http://www.geni.com/people/Vesna-Sardeli%C4%87/4169920 used to keep in touch with them while she lived in Argentina, she also mentioned some hotel named Orebic