She will never admit it, but it was Natasha Romanoff who made the decision to release all SHIELDRA's files, not the Black Widow.
The Black Widow would have thought about the agents she was compromising, the reasons why certain information was classified. She would have thought about and weighed consequences.
All Natasha thought about was betrayal. SHIELD was her fresh start, a chance to balance the red in her ledger. To find it was actually HYDRA… She burned to tear them apart, expose their lies.
All Natasha saw was the lines in her ledger, the black ink turning to red.