The leak came the same week the FBI arrested two former Rosselló administration officials in a federal corruption investigation. And the island has been mired in a 13-year economic recession.
She says the protest was about more than the governor's resignation.
"We have a basic common goal, which is Ricki's resignation," Rivera said. "But is also a deeper message that comes back time and time again, which is about collective power."
She expressed it in Spanish and English: "Somos más y no tenemos miedo. There are more of us, and we have no fear."
Rivera watched as people dressed in black T-shirts, waving the U.S. island territory's flag, filled major highways.
Then she was pepper sprayed by police, and she says she became enraged.
"How dare they? Over a million people marched, and they pepper sprayed us for a man who laughed at our dead," she said.
Then she said there was a shift in the mood and the purpose of the protests.
"Fear was the last thing I felt, because other protestors, those who were wearing masks, helped me. When I couldn't see they led me," she said.
Rosselló announced on Wednesday that he would resign, making him the first governor to do so in the modern history of Puerto Rico.
Rivera said her takeaway from the experience extended beyond the resignation. It was about fixing a corrupt system and failing schools. The protests brought together every section of Puerto Rico in what she describes as a loving and creative way, reminding herself and everyone of their collective power.
"We can remove a leader that does not serve us. Everyone lost their fear after Maria. This is euphoria rooted in this collective self knowledge."