Why do angels serve Mary in heaven?

Angels serve Mary in heaven as a recognition of her unique role as the Mother of God and her exceptional holiness. In Christian theology, Mary is venerated as the highest of all creatures, and her cooperation in God's plan of salvation elevates her status among the heavenly hosts. Additionally, serving Mary reflects the honor and reverence she commands due to her vital participation in the Incarnation and her ongoing intercessory role for humanity. Thus, the angels' service to her is a manifestation of their devotion and acknowledgment of her significance in the divine order.