Explanation: In Classical Antiquity in general, especially amongst the nobility, marrying young was common - and with large age gaps between men and women, as women generally had far fewer rights than men.
According to Greek legends (almost certainly mythical, for the logistics of it if nothing else), Scythian nomad women would only marry after slaying enemies in battle - numbers vary from 1 to 3. This is obviously incredibly impractical and unlikely to be literally true, but reflects the Greek perception of Scythian women as independent warriors. She can slay me any day!