I'm not an Italy expert, but the state I live in has the highest Italian population in
America. So I guess I still know a fair bit about Italian names. I've seen
Rosa used, though it is more often on middle-aged to older women. But it wouldn't seem out of place on a younger person. I've never seen
Rosanna used, but
Luisa is fairly common. I don't think
Siena is really used that often as a name. Here are some other names that are common in my area.
MichaelaVictoriaNinaSandraLucettaMarisa /
MarissaGabriellaMilanMariaAnnaMonicaIsabellaNadiaCinzia (CHIN-see-uh)
Gianna (super common. I know about 6 of them)
CaterinaEva
If you want a list of boys' names I can give one to you, too.