This name belongs to the Polish nun and mystic,
St. Maria Faustyna Kowalska. Perhaps better known as "the Apostle of the Divine Mercy," Faustyna detailed her visions of Christ in her diary, in which she noted her conversations with Him. Her writings are a beautiful reminder on the importance of mercy in our lives. Hopefully your own little Faustyna, or Faustina, will prove just as merciful.