It wasn't that simple in the ancient world and honestly the whole ruining thing is a modern religious idea. Shame wasn't a major part of the Greek religions, it comes far more from Christianity. A girl was usually a maiden until she's a mother, I don't think the Greeks cared that much about virginity, the Romans did more.

And the real warning with all of this just looking at the language you're using, the past is another country, we will never know for certain but putting too many of our ideas back is tricky. Think of how the gods had realms, men and women had different realms, there were some sanctuaries and festivals that were only for women and girls. It was a very different way of looking at things and since Thalia is from a modern look at these ancient ideas, there's that as well.