Why does the Blessed Virgin Mary bear the title "Seat of Wisdom" (Lat: sedes sapientiae)? There are two reasons. The first regards wisdom absolutely as the incarnate Son of God, our Lord Jesus Christ. Saint Paul identifies Christ as the "wisdom of God".
But to those who are called, both Jews and Greeks, Christ is the power of God and the wisdom of God...He is the source of your life in Christ Jesus, whom God made our wisdom, our righteousness and sanctification and redemption (1 Cor 1:24, 30).Christ fulfills the Old Testament tradition of the primordial Wisdom (חחמה,"Chokmah") of the Lord. St. John used the concept by identifying Christ as the Divine Word or Logos of God (John 1:1-13). As Wisdom Incarnate, Christ is seated on the lap of His Blessed Mother. Mary is the throne from which Christ rules the universe.
Secondly, our Lady is the seat of wisdom relatively as the human fulfillment of "Lady Wisdom" presented in the Book of Proverbs and especially in Proverbs 31 as the ideal wife and mother.
Because she is the mother of Wisdom (Jesus Christ), she participates in wisdom preeminently. She is Lady Wisdom by virtue of her role as Theotokos.
In conclusion, Christ is wisdom absolutely and so Mary is the "Seat of Wisdom" because she bore Christ in her womb and upon her lap. Mary is wisdom relatively in that she is personificaltion Lady Wisdom in the tradition of the Book of Proverbs.