Sonia Belmont - 17 (not only did she have sex before marriage, but she was underage!)
You forget Claimh Solais. According to our history, people during the medieval period and the the Roman Empire were getting married at at least age 14. People didn't live very long back then (at least 30 to 40 years or so. More if you were lucky like Ramses II. 89 ys) so it made sense to start a family before your biological clock ran out on ya.