If there was one thing that Vivi knew, it was rebuilding a country after a horrible civil war and years of drought was a difficult and time exhaustive task that was absolutely draining, not to mention expensive. It required a strong sense of duty, unity, and a love of the people.
The results, however, were extremely satisfying.
Vivi knew that staying in Alabasta was the right decision. She had probably known all along that being with her people was the morally correct and responsible thing to do. After all, the rebellion had left deep wounds that didn't just heal. Bringing Alabasta back to its former glory took time and effort, and more time and more effort, not to mention all the determination it required to simply move forward rather than dwell in the past.
Throughout the whole process, Vivi missed her friends terribly. The things that she had gone through with the Straw Hats had brought them together in such a way where she couldn't think of them as just friends. According to Chaka and Pell it was more like the bond between solders who had experienced war together. Which Vivi supposed was fitting, even though they were pirates and she was a princess.
Being separated from the Straw Hats might have been slightly more bearable if they weren't wanted by the World Government (a fact that gave Vivi more than a little guilt, seeing as how it was Crocodile's defeat that put them on the map). As it was she couldn't call or even write them. All she could do was keep a close eye on the papers and silently root for the irregular group that had saved her home.
And boy oh boy did they make the papers. First was the Enies Lobby incident, then Sabaody, with Impel Down and Marineford soon to follow. The world was buzzing with the exploits of the "Supernovas", comparing Luffy with the likes of Law, Kidd, and Drake.
Then, after one last public showing, they disappeared. Poof, gone, with only a cryptic clue as to their whereabouts. Days turned into weeks, weeks into months, and months into years without word of the Straw Hats. Eventually the puzzling vanishing act became old news, and the papers moved onto other, more pressing matters. General consensus was that Luffy was dead and his followers disbanded.
Those speculative reports hurt the worst. Vivi didn't think any of them were dead, of course, but not knowing was a terrible burden to bear. The pain Luffy had after the loss of his brother must have been horrible, and there was nothing she could do to help.
Vivi hated her feeling of helplessness. When her country had been in danger, the course of action had been clear. Now she didn't even know where her friends were. There was no course of action to be taken, because there was quite literally nothing she could do.
Kohza had noted once that sometimes she cared too much for her own good. Vivi had countered by saying it was her love for her family and her country that gave her the drive to continue.
So Vivi continued with the rebuilding efforts, and as her father's health declined she took a more active role in the rule of the kingdom. Gradually she was entrusted not only with internal affairs, but international ones as well. Slowly but surely she transformed from a naïve princess who was willing to put the succession of the royal line at risk (not to mention her life) to diffuse a rebellion into an intelligent and idealistic heir-apparent.
With this newfound power came the ability to sit in on international meetings, making her privy to sensitive top-secret information about all sorts of persons of interest (all in the name of international security, of course). Vivi got a good view of how the world was run, both the good and the bad. The aftermath of the Battle for Marineford caused major shake ups throughout the world; and between another pirate surge and the Revolutionaries the leaders of the world had their hands full.
Somewhere between meetings with her father, coordinating events with Chaka and Pell, and surveying Alabasta with Kohza a small idea surfaced in her mind. The Straw Hat pirates were among the world's "worst generation". The bounty on Luffy's head was astronomical for a man his age, and the exploits of his crew were quickly becoming legend. He and his crew would need all of the powerful friends he could get once he resurfaced. And while she was just a princess of a rebuilding nation, Alabasta's stock was rising.
Igaram had subtly warned against taking unnecessary risks. Pell and Kohza had refrained from giving advice. Her father, with all the wisdom that came with being king, had only told her to follow her heart.
Vivi, once again, knew what the right thing to do was. She loved the Straw Hats, just as deeply as she loved her kingdom. She had followed their adventures from afar, quietly wondering how much the papers really got right, wishing them well, and wondering if Luffy ever found that musician he wanted.
Now she would use her position to help in whatever way she could. She would do it for the silly captain who was willing to risk his life for a friend and the loyal and determined swordsman with the rough exterior. She would continue to fight for bossy navigators, love-struck cooks, shy doctors, and lying sharpshooters. For former enemies and friends she had never met she would gather information that may one day save their lives.
Kohza had once accused Vivi of caring too much. At the time he had been referring to how she had infiltrated Baroque Works, but it had become a sort of recurring joke of sorts for all the late nights she spent stressing about some policy or law, or when she started fretting over taxes or the state of the nation's army.
Her answer was always the same. She would do anything for the things she loved, because those were the things (or in this case, the people) that made her life worth living.