Short answers, pulled from the story.
Agrippina the Younger, born Julia Agrippina on the 6th of November AD 15, was Roman empress from AD 49 to 54 and mother of the emperor Nero. She was the great-granddaughter of Augustus, the only living empress to appear unambiguously on official Roman coinage, and the woman after whom the city of Cologne was named, making her one of the most powerful women in the Julio-Claudian dynasty.
Agrippina married her uncle, the emperor Claudius, on New Year's Day in AD 49 after Roman law was changed to permit a union that had previously been considered incestuous. She was granted the honorific title of Augusta in AD 50 and quickly built a network of loyal allies within the imperial administration, including the head of the Praetorian Guard.
Agrippina died on the 23rd of March AD 59, murdered on the orders of her son Nero. After surviving a rigged boat designed to sink beneath her, she was killed by men Nero sent to her villa, including the freedman Anicetus, the trierarch Herculeius, and the marine centurion Obaritus. Nero told the Senate she had plotted against him and died by suicide.
Ancient sources including Tacitus, Suetonius, and Cassius Dio claim Agrippina poisoned Claudius on the 13th of October AD 54 with a plate of deadly mushrooms at a banquet. Modern historians note it is also possible that Claudius died of natural causes, as he was 63 years old and in poor health.
Claudius founded a Roman colony on the Rhine in AD 50 and named it Colonia Claudia Ara Agrippinensium in Agrippina's honor, the city known today as Cologne, Germany. It was the only Roman colony ever named after a Roman woman. Agrippina was born near that location at a Roman outpost on the Rhine.
Agrippina did write memoirs covering her life and her family's misfortunes. Tacitus explicitly cites them in Annals 4.53 as a primary source for information about her father Germanicus. The memoirs have not survived, leaving a significant gap in the historical record from a female perspective on the Julio-Claudian court.