On page 37 of the book, (or 40 on PDF) it says: « Whenever thou wishest to obtain favours from me », said Mary to lady Fortunatina Agrelli, « make the Novena of impetration once, twice, nay three times, and at the same time recite my Rosary; if the grace be granted to thee, make likewise three Novenas of thanksgiving. » Sir Agrelli's daughter accordingly made three novenas in succession and was miraculously cured.
On page 38-39 it says: During the novena, if possible, you should say every day your beads, for, our Lady promised to saint Dominic that she will bestow a special favour on all those who recite her entire rosary. You need not say the whole rosary at once: the fifteen decades may be recited at different times, either at tome or out of doors, in bed or al Work, all at your own good treasure; but it is essential to meditate on the mysteries while saying the beads.
Each novena is nine days. Three novenas in succession would be 27 days.
The prayers of the novena of impetration is on page 103 (106 on the PDF) and the prayers of the novena of thanksgiving is on page 114 (117 on PDF)
This is known as the 54 days Rosary Novena in modern times, but the prayers of the novena of impetration and novena of thanksgiving is forgotten. And the original words of Our Lady was that the additional three novenas of thanksgiving is to be made if the grace is granted. But nowadays people say that one should pray the Novena regardless of whether the grace was granted or not.