Well, if you bothered to read the dialogue of the game you would have noticed that at the beginning of the last episode of Treasure of Nadia the MC himself told Emily, in Squallmart, that Kaley WAS a virgin. If you think that I'm wrong and the MC is wrong, or should I say the author of the game and creator of its characters is wrong, look up the word "virgin" in a dictionary and possibly words like "sexual intercourse" and "coitus" afterwards in order to understand that virginity is the state, in both female and male humans, of never having had penetrative penile-vaginal intercourse with a member of the opposite sex.
Since I'm not your parent, relation, teacher or somebody who cares about you it's not up to me to educate you, so I'm going to leave it at that but would urge you to read the dialogue of Treasure of Nadia in future so as not to miss out on its story.
(Although candidly, that said, I couldn't really care less whether you take my advice on board or not.) I really honestly and truly cannot understand why so many individuals hereabouts are quite so uninterested in and oblivious to ToN's excellent plot and storyline.
(Too busy masturbating and/or unpractised in reading English I suppose.)
It is indeed a pity.