Spoiler warning: Plot and/or ending details follow.
After a fungal infection made the food supplies inedible, Adrian Kodos engineered a vote of no confidence in Ribeiro and had her removed from office. Kodos was quickly voted in to replace her as Governor. Kodos and his people arrested and imprisoned Ribeiro and her staff. Kodos then had 4,000 colonists murdered in an attempt to preserve the colony's food supplies until help could arrive. Among those who had died in the massacre was Ribeiro's fiancée, which she did not find out about until she was released from jail.
Following the arrival of the Starfleet starship USS Narbonne, Riberiro was allowed to resume her post as Governor. She coordinated the relief efforts and the hunting down of Kodos with Starfleet officers Philippa Georgiou, Gabriel Lorca, and Captain Aurobindo Korrapati. Ribeiro, along with many of the colonists were determined to stay on Tarsus IV and rebuild the colony. (DSC novel: Drastic Measures)