Catholic apparitions of Mary and miracles have always been a part of the rich tapestry of Catholic history. While skeptics are quick to dismiss miracles and visions as either madness or coincidence, there is a long record of documentation proving the authenticity of such events.
Miracles such as Our Lady of Guadalupe and Our Lady of Fatima are well documented visions where there is either physical evidence as in the case of Our Lady of Guadalupe or thousands of witnesses as was the case of Our Lady of Fatima.
It is important to note that the Catholic Church typically spends years and even decades investigating these events and sometimes never makes a declaration that a specific event is miraculous. The Church also relies on independent medical analysis to determine whether or not miraculous cures are truly miraculous or can be scientifically explained.
While the Catholic Church may declare particular visions and miracles to be truly "heaven sent", the Church doesn't require that Catholics believe that these events are truly miraculous and also says that nothing contained in visions is required as a matter of Faith to get to Heaven.