Gaius Caesar
Gaius Caesar (Latin: "Gaius Julius Augusti f. Divi n. Caesar"; 20 BC – 21 February AD 4) was consul in AD 1 and the grandson of Augustus, the first emperor of the Roman Empire.
Although he was born to Marcus Vipsanius Agrippa and Julia the Elder, Augustus' only daughter, Gaius and his younger brother, Lucius Caesar, were raised by their grandfather as his adopted sons and joint-heirs to the empire.
He would experience an accelerated political career befitting a member of the Julio-Claudian dynasty, with the Roman Senate allowing him to advance his career without first holding a questorship or praetorship, offices that ordinary senators were required to hold as part of the "cursus honorum".
In 1 BC, Gaius was given command of the eastern provinces, after which he concluded a peace treaty with King Phraates V of Parthia on an island in the Euphrates.
Shortly afterward, he was appointed to the office of consul for the following year, 1 AD.
The year after Gaius' consulship, Lucius died at Massilia in the month of August.
Approximately eighteen months later, Gaius died of an illness in Lycia.
He was married to his second cousin Livilla
but they did not have children.
In 4 AD, following the deaths of Gaius and Lucius, Augustus adopted his stepson, Tiberius, as well as his sole-surviving grandson, Agrippa Postumus.
Mona Hopton Bell
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She was the grandmother of the painter Jean H. Bell.
Hubba bint Hulail
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Kaoru Hatoyama
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Julia the Elder
Julia the Elder (30 October 39 BC – AD 14), known to her contemporaries as Julia Caesaris filia or Julia Augusti filia
(Classical Latin: or), was the daughter of Augustus Caesar, the first Roman Emperor, and his second wife, Scribonia.
Julia was also stepsister and second wife of the Emperor Tiberius; maternal grandmother of the Emperor Caligula and the Empress Agrippina the Younger; grandmother-in-law of the Emperor Claudius; and maternal great-grandmother of the Emperor Nero.

Question: Who is the maternal grandmother of Gaius Caesar?