More from the HomepageBy DAVID BILLERALMUDENA CALATRAVAandTATIANA POLLASTRIAssociated PressmoreRIO DE JANEIRO — With her 21st birthday fast approaching, Sara left the home she shares with her mother for her first trip on a plane. She didn't tell her family the real reason she'd taken out a loan for 5,000 Brazilian reais ($1,000).Two days later and several hundred miles away, a 25-year-old woman packed a backpack in her one-bedroom Sao Paulo apartment and left for the airport with her boyfriend.Both women were bound for the Argentine capital, Buenos Aires, seeking something forbidden in...…More from the HomepageBy DAVID BILLERALMUDENA CALATRAVAandTATIANA POLLASTRIAssociated PressmoreRIO DE JANEIRO — With her 21st birthday fast approaching, Sara left the home she shares with her mother for her first trip on a plane. She didn't tell her family the real reason she'd taken out a loan for 5,000 Brazilian reais ($1,000).Two days later and several hundred miles away, a 25-year-old woman packed a backpack in her one-bedroom Sao Paulo apartment and left for the airport with her boyfriend.Both women were bound for the Argentine capital, Buenos Aires, seeking something forbidden in...WW…