The 1968 General Chapter elected Mother Rosalia Sosso to succeed Mother Speranzina as Superior General. Born in Pittsburgh, Pennsylvania, in 1915, Mother Rosalia entered the Congregation in 1935. She soon distinguished herself for her exemplary religious life and apostolic zeal as teacher, music instructor, principal, and formation directress. ln 1960, she assumed the office of Provincial Superior of the United States Province. Mother Rosalia, faithful daughter of the Church and of Mother Clelia, was able to guide the Congregation during the post-conciliar period to a healthy and balanced renewal in harmony with the Church's guidelines and the signs of the times. Under her steady leadership, successive Chapters accomplished the following:
- the writing of the new Constitutions, approved by the SCRIS on June 26, 1981
- the writing of the General Directory, approved by the eleventh General Chapter in 1980
- the updating of the manual Apostles at Prayer (eleventh General Chapter, 1980) and the adoption of the Liturgy of the Hours.
Mother Rosalia continued the work and research begun by Mother Speranzina concerning Mother Clelia and was responsible for numerous publications regarding her life and spirituality thus paving the way for the introduction of the Foundress' cause of beatification. Always attentive to the Apostles' ongoing formation, Mother Rosalia bought the "International Center of Spirituality" at Rocca di Papa in 1972. In 1975 she brought to this Center Sisters from all the Provinces to celebrate the Holy Year; in 1983 she invited the Provincial Superiors to celebrate the Holy Year of the Redemption; and in 1985 she welcomed students and sisters from the Apostles' secondary schools during the International Youth Year. In addition, numerous Sisters were invited to Rome for formation programs and retreats. In 1974 Mother Rosalia initiated the possibility of a year of spirituality in Rome for Apostles from every Province. She also promoted the missionary expansion of the Congregation opening missions in the state of Para, in northern Brazil and new works in each of the nations where the Sisters carry out their ministry. Mother Rosalia resided in the community at Sacred Heart Manor in Hamden, CT, U.S.A from 2000 until her death on July 15, 2012.