69 Moreover, as the obligation of Our Apostolic Office demands, We urge fathers and mothers to willingly offer to the service of God those of their children who are called to it. But if this be a source of trouble, sorrow or regret, let them seriously meditate upon the admonition which Ambrose gave to the mothers of Milan. "The majority of the young women whom I knew wanted to be virgins were forbidden to leave by their mothers. . . If your daughters want to love a man, the laws allow them to choose whom they will. But those who have a right to choose a man, have no right to choose God."
Source: Sacra Virginitas (Vatican.va)