If you want to refute her statement, you'd do better to point to the Great Schism.
There were always other groups like the anabaptists that rejected the Roman Pope and Catholic hierarchy. Below is an excerpt of non-catholic church history from the following link. Church History
During all this time of the rise and development of false doctrines and practice in the churches, there were scattered through Europe, Asia, and Africa, groups of dissenting churches which refused to acknowledge the Roman pope and sought to follow the New Testament. Some early groups were the Montanists, Novatians, and Donatists. Later groups included the Petrobrusians, Waldensees, and Anabaptists. Catholic historians call most of these sects "Anabaptists". They were mercilessly persecuted throughout the centuries until after the Reformation, and some persecution against them has continued to modern times.
Though these groups did not carry the name "Baptists", many of them did hold various Baptist tenents, such as separation of church and state, spiritual democracy, salvation by grace apart from sacraments, believers' baptism, and immersion as the mode of baptism. churches holding these truths cherished New Testament principles. They shared with Baptists the desire to follow Christ's will for His churches.
When the Reformation came, numerous new non-Catholic groups appeared. Some of them became the large Protestant denominations of today. They all rejected many of the heresies of the Roman Catholic Church, but most of them retained some teachings which had no foundation in the New Testament. In the centuries since the Reformation, other denominations have been formed until there are now hundreds of separate denominational organizations. Some of them have departed far from using the New Testament as their only rule of faith and practice.