And it is the same Catechism, in No. 493, that explains the unique condition of the Mother of God during her life:
«The Fathers of the Eastern tradition call the Mother of God “the All Holy” (Panagia), they celebrate her “as immune from every stain of sin and as shaped and made a new creature by the Holy Spirit” (LG 56). By the grace of God, Mary has remained pure from all personal sin throughout her life.
However, Mary complied with the ritual established by law for the purification of women, and she also accepted that Jesus be circumcised. She remained unseen for 40 days, abstaining from entering the temple and participating in the cult ceremonies. She then went to Jerusalem with Jesus in her arms, gave the offerings in thanksgiving and, for her atonement, she presented the Son before the priest, who offered him to the Heavenly Father. The custom required parents to pay five shekels in exchange for the priest returning the baby to its mother’s arms. Of course, it was always possible that God would claim him again later.