I agree with ziggKogg; "siamo" can only have one meaning in this context. For any situation the word would be "Io sono" (I am), "tu sei" (you are), "lui/lei è" (He/she is), "Noi Siamo" (we are), "voi siete" (you (plural) are), "Loro sono" (they are). Given the above, "siamo" comes from "we", therefore "We are" and "donne" being the plural of "donna" = women. Siamo donne = we are women.
Not really, it's the same in Spanish, you can drop the personal pronoun.
Donne is the plural form of woman = women
Siamo is the plural form of the verb "to be" = we are
So the sentence reads "We are women = "Siamo donne"
I wrote siamo donne here, so got it right, but if I wanted to say they are women, could I say sono donne? would that be understood that I meant they are and not I am women?