I’m a Catholic, modern woman in my late 20s, and both from the Scriptures and within my heart I feel confident that God wants only one thing from us — sincerity and love. It’s actually only the Pharisees Jesus condemns for being “hypocrites” — following the letter, not the conscience. Never does he condemn any woman they condemned as “sinful”.
In general, “saving oneself for marriage” is part of the philosophy that was used to protect women before the 20th century, since throughout most of history, marriage was a woman’s only token of a safe future. So women were supposed to enter marriage young and childless and men were supposed to be responsible for the family for life (with no official divorce allowed) . It was kind of a social pact, like Schopenhauer notes. And it was a useful one for the time.
Today, as modern women we’ve assumed personal responsibilities over our body and life. Sex, as long as no abortion of human life results from it and adequate protection is used, is no more than a personal choice with no shame attached.