Antonia Minor

Antonia Minor (January 31, 36 B.C.E - May 1, 37 C.E) is the mother of Claudius and Germanicus.

Family
Antonia is a daughter of Mark Antony and Octavia Minor.

Marriage and Issue
She married Nero Claudius Drusus and is the mother of popular Roman General, Germanicus, and Claudius, a future Emperor of Rome.

The Rightful Heir
Antonia is not shown in the episode, but it is mentioned that after Caligula's brothers and mother are killed or exiled in the Treason Trials under Tiberius, they stay with her.