Many of us were surprised and stunned by this call to fasting in general, let alone for two days a week. Many considered this to be excessive, unrealistic and impossible. However, even a quick glance at the history of fasting shows that Jews used to fast two days a week, on Mondays and on Thursdays. The Gospel according to Luke (Lk 18:9-13) mentions the Pharisee who prays in the Temple and thanks God for his prayer, his fasting twice a week and his taking care of the poor. However, he was not justified, because he judged the tax collector who also prayed in the Temple some distance away. Jesus neither devaluated fasting nor did He forbid fasting twice a week; He forbade judging others.
Mary is the Queen of the Prophets, and all the Prophets called for conversion, fasting and prayer as conditions for peace. Our Lady has no better or different means than those, by which the Prophets called to peace, namely conversion, prayer, fasting and firm faith.