36 Our holy mother, the Church, holds and teaches that God, the first principle and last end of all things, can be known with certainty from the created world by the natural light of human reason.
105 "For Holy Mother Church, relying on the faith of the apostolic age, accepts as sacred and canonical the books of the Old and the New Testaments, whole and entire, with all their parts, on the grounds that, written under the inspiration of the Holy Spirit, they have God as their author, and have been handed on as such to the Church herself."
167 "I believe" is also the Church, our mother, responding to God by faith as she teaches us to say both "I believe" and "We believe".
169 Salvation comes from God alone; but because we receive the life of faith through the Church, she is our mother: "We believe the Church as the mother of our new birth, and not in the Church as if she were the author of our salvation." Because she is our mother, she is also our teacher in the faith.
171 As a mother who teaches her children to speak and so to understand and communicate, the Church our Mother teaches us the language of faith in order to introduce us to the understanding and the life of faith.
181 The Church is the mother of all believers. "No one can have God as Father who does not have the Church as Mother" (St. Cyprian, De unit. 6: PL 4, 519).
507 At once virgin and mother, Mary is the symbol and the most perfect realization of the Church: "the Church indeed. . . by receiving the word of God in faith becomes herself a mother. By preaching and Baptism she brings forth sons, who are conceived by the Holy Spirit and born of God, to a new and immortal life. She herself is a virgin, who keeps in its entirety and purity the faith she pledged to her spouse."
757 "The Church, further, which is called 'that Jerusalem which is above' and 'our mother', is described as the spotless spouse of the spotless lamb.
808 The Church is the Bride of Christ: he loved her and handed himself over for her. He has purified her by his blood and made her the fruitful mother of all God's children.
813 What an astonishing mystery! There is one Father of the universe, one Logos of the universe, and also one Holy Spirit, everywhere one and the same; there is also one virgin become mother, and I should like to call her "Church."
1141 "Mother Church earnestly desires that all the faithful should be led to that full, conscious, and active participation in liturgical celebrations which is demanded by the very nature of the liturgy, and to which the Christian people, 'a chosen race, a royal priesthood, a holy nation, a redeemed people,' have a right and an obligation by reason of their Baptism."
1163 Holy Mother Church believes that she should celebrate the saving work of her divine Spouse in a sacred commemoration on certain days throughout the course of the year.
1203 In "faithful obedience to tradition, the sacred Council declares that Holy Mother Church holds all lawfully recognized rites to be of equal right and dignity, and that she wishes to preserve them in the future and to foster them in every way."
1249 "With love and solicitude mother Church already embraces [catechumens] as her own."
1667 Holy Mother Church has, moreover, instituted sacramentals.
1683 The Church who, as Mother, has borne the Christian sacramentally in her womb during his earthly pilgrimage, accompanies him at his journey's end, in order to surrender him "into the Father's hands."
2016 The children of our holy mother the Church rightly hope for the grace of final perseverance and the recompense of God their Father for the good works accomplished with his grace in communion with Jesus.
2040 Thus a true filial spirit toward the Church can develop among Christians. It is the normal flowering of the baptismal grace which has begotten us in the womb of the Church and made us members of the Body of Christ. In her motherly care, the Church grants us the mercy of God which prevails over all our sins and is especially at work in the sacrament of reconciliation. With a mother's foresight, she also lavishes on us day after day in her liturgy the nourishment of the Word and Eucharist of the Lord.
2103 Mother Church rejoices that she has within herself many men and women who pursue the Savior's self-emptying more closely and show it forth more clearly, by undertaking poverty with the freedom of the children of God, and renouncing their own will
2212 The fourth commandment illuminates other relationships in society. In our brothers and sisters we see the children of our parents; in our cousins, the descendants of our ancestors; in our fellow citizens, the children of our country; in the baptized, the children of our mother the Church
Many of these paragraphs from the Catechism are in turn quoting from the early Church fathers, and from various Church documents, so you can begin to see how widespread and beloved is this image of Church as our mother.
In the words of St. Cyprian, "No one can have God as Father who does not have the Church as Mother."