Two Sister Lucys of Fatima?

If she expressed such serious concern about the importance that the Third Secret be revealed in 1960, why was she silent about it for the next 40 years? Contradicting what she had previously stated, how could she confirm the supposed secret that was unveiled by the Vatican in 2000, along with an “official interpretation” by Cardinal Ratzinger and Archbishop Tarcisio Bertone who then declared the Fatima episode closed, “a part of the past” ?