In "The Alchemist," what significant role does the gypsy woman that Santiago met play in helping to reach his goal?

The gypsy woman merely reiterates that the boy, who dreamed that he went to the Pyramids of Egypt and found a great treasure, must go on his quest.  The reason Santiago went to see her was because he'd had the same dream twice, and he was hoping for a more in-depth explanation.  When she merely reiterated the obvious message of the dream (go to the Pyramids), he at first was discouraged in her so-called abilities (but happy that he didn't have to pay for her services because she'd requested 10% of the treasure if and when he found it..and he did not take the dream seriously at that point).  However, like many ideas, once they have been brought to mind and then confirmed by another, they have a way of growing on a person's imagination.  After speaking with her, the dream seemed to become more real to Santiago, and then his chance meeting with the King of Salem further confirmed that he should go to the Pyramids.  If he had not spoken with the gypsy woman, he might have just ignored the dream and would never have sought out to fulfill his Personal Legend.  Happily, when Santiago eventually does find the treasure, he remembers his promise to the old woman and gives her 10%.