Incorrect.
Pope Benedict XV tells us, "With Her suffering and dying Son She suffered and almost died, so did She surrender Her mother's rights over Her Son for the salvation of human beings, and to appease the justice of God, so far as pertained to Her, She immolated Her Son, so that it can be rightly said, that She together with Christ has redeemed the human race." (Admodum probatur, June 20, 1917)
Pope St. Pius X explains congruous and condign merit, "from this common sharing of sufferings and will, She merited to become most worthily the reparatrix of the lost world, and so the dispensatrix of all the gifts which were gained for us by the death and blood of Jesus. ... since She was ahead of all in holiness and union with Christ, and was taken up by Christ into the work of human salvation, She merited congruously, as they say, what Christ merited condignly, and is the chief minister of the dispensation of graces. (Ad diem illum, Feb. 2, 1904)
http://www.piercedhearts.org/hearts_jesus_mary/heart_mary/mystery_coredemptrix_papal_magisterium.htmB
"The word "Coredemptrix" makes its preliminary appearance on the magisterial level by means of official pronouncements of Roman Congregations during the reign of Pope Saint Pius X (1903-1914) and then enters into the papal vocabulary.
1. The term first occurs in the Acta Apostolicæ Sedis in a response to a request made by Father Giuseppe M. Lucchesi, Prior General of the Servites (1907-1913), requesting the elevation of the rank of the feast of the Seven Sorrows of Our Lady to a double of the second class for the entire Church. The Sacred Congregation of Rites, in acceding to the request, expressed the desire that thus "the cultus of the Sorrowful Mother may increase and the piety of the faithful and their gratitude toward the merciful Coredemptrix of the human race may intensify". [18]
2. Five years later the Sacred Congregation of the Holy Office in a decree signed by Cardinal Mariano Rampolla expressed its satisfaction with the practice of adding to the name of Jesus that of Mary in the greeting "Praised be Jesus and Mary" to which one responds "Now and forever":
There are Christians who have such a tender devotion toward her who is the most blessed among virgins as to be unable to recall the name of Jesus without accompanying it with the glorious name of the Mother, our Coredemptrix, the Blessed Virgin Mary. [19]
3. Barely six months after this declaration, on 22 January 1914, the same Congregation granted a partial indulgence of 100 days for the recitation of a prayer of reparation to Our Lady beginning with the Italian words Vergine benedetta. Here is the portion of that prayer which bears on our argument:
O blessed Virgin, Mother of God, look down in mercy from Heaven, where thou art enthroned as Queen, upon me, a miserable sinner, thine unworthy servant. Although I know full well my own unworthiness, yet in order to atone for the offenses that are done to thee by impious and blasphemous tongues, from the depths of my heart I praise and extol thee as the purest, the fairest, the holiest creature of all God's handiwork. I bless thy holy Name, I praise thine exalted privilege of being truly Mother of God, ever Virgin, conceived without stain of sin, Coredemptrix of the human race. [20]
On the basis of these last two instances Monsignor Brunero Gherardini comments that
The authority of that dicastery [the Sacred Congregation of the Holy Office], now designated as 'for the Doctrine of the Faith', is such as to confer on its interventions a certain definitive character for Catholic thought. [21]
4. The first papal usage of the term occurs in an allocution by Pope Pius XI (1922-1939) to pilgrims from Vicenza on 30 November 1933:
From the nature of His work the Redeemer ought to have associated His Mother with His work. For this reason We invoke her under the title of Coredemptrix. She gave us the Savior, she accompanied Him in the work of Redemption as far as the Cross itself, sharing with Him the sorrows of the agony and of the death in which Jesus consummated the Redemption of mankind. [22]
5. On 23 March 1934, the Lenten commemoration of Our Lady of Sorrows, Pius XI received two groups of Spanish pilgrims, one of which was composed of members of Marian Congregations of Catalonia. L'Osservatore Romano did not publish the text of the Pope's address, but rather reported his principal remarks to these groups. Noting with pleasure the Marian banners carried by these pilgrims, he commented that they had come to Rome to celebrate with the Vicar of Christ
not only the nineteenth centenary of the divine Redemption, but also the nineteenth centenary of Mary, the centenary of her Coredemption, of her universal maternity. [23]
He continued, addressing himself especially to the young people, saying that they must:
follow the way of thinking and the desire of Mary most holy, who is our Mother and our Coredemptrix: they, too, must make a great effort to be coredeemers and apostles, according to the spirit of Catholic Action, which is precisely the cooperation of the laity in the hierarchical apostolate of the Church. [24]
6. Finally Pope Pius XI referred to Our Lady as Coredemptrix on 28 April 1935 in a Radio Message for the closing of the Holy Year at Lourdes:
Mother most faithful and most merciful, who as Coredemptrix and partaker of thy dear Son's sorrows didst assist Him as He offered the sacrifice of our Redemption on the altar of the Cross ... preserve in us and increase each day, we beseech thee, the precious fruits of our Redemption and thy compassion. [25]
Because of this usage of the term Coredemptrix in magisterial docuмents and addresses by the Supreme Pontiff Canon René Laurentin wrote thus in 1951 about its employment: ... the term henceforth requires our respect. It would be gravely temerarious, at the very least, to attack its legitimacy. [26]"