Proto-Indo-European Roots

Root/Stem: *gwen-
Meanings:  a woman, a wife
Related to: Greek guné (a woman, a wife) - from *guná
Common Celtic *ben- (a woman), gen. sg. *bnás (of a woman) > 
Old Irish ben, Irish Gaelic bean, Scottish Gaelic bean, Manx ben, Cornish benen, Welsh benyw
Common Anatolian *gwana (a woman) 
Luwian wanatti
Avestan [email protected]á (a woman); 
Persian & Tadjik zan
Sanskrit janis, gná (a woman, a goddess), Singhalese gani
Kashmiri zanana
Phrygian bon-ekos (a wife) - a suffix added
Armenian kin (a woman, a wife), gin
Tocharian A s'än (a woman), Tocharian B s'ana
Common Germanic *kwen- (woman) > 
Gothic qino (a woman), qéns (a queen), Old English cwén (woman, wife, queen), Old High German cwán, Old Norse kwaen; 
English queen, Scottish queyn (a queen), Swedish kvinna (a woman), Icelandic kona, kvennmaor, Faroese kona, Danish kvinde, Dutch kween (old cow), Frisian kwyn
Common Baltic *gen- (a woman) > 
Old Prussian voc. sg. genno (woman!), *gená (a wife, a woman), Sudovian *genâ (a woman, a wife)
Common Slavic *z'ena (a woman) > 
Belorussian z'ana, Bulgarian & Polish & Serbo-Croatian & Slovene & Czech & Slovak & Ukrainian & Russian z'ena, Sorbian z'ona
Notes: The stem must be rather archaic - the original meaning was not just "a woman", but "an honoured woman", which witnesses that it was born in ancient matriarchate times. Germanic meaning "queen" and Sanskrit "goddess" make this more than just a version. 
The gender is in most cases feminine, which is natural; however, Old English is neuter. In majority of languages this noun was of a-stems.