Steve-- she is not the police, a judge, a detective or any sort of figure in the criminal justice system. The only way it would present a problem is if she opened a piece of mail. That is a felony. Otherwise, finding evidence in a folder hidden in a briefcase is not a legal matter. She did not go thru that briefcase or folders looking for evidence of sexual abuse in the congregation, ie looking for probable cause. Her intent was basically to find "bochinche" , Puerto Rican slang for extreme gossip. In fact, if she does not report, as someone else has stated-- she becomes ACCESSORY TO A CRIME.
Why is there even debate about what she should do?
REPORT THIS CRIME IMMEDIATELY.