Caligula sure looks like his sister!

[Roman Collector]

What a resemblance!

Agrippina the Younger, Marble bust, first century A.D. Naples National Archaeological Museum.

Caligula, Marble bust, Copenhagen, New Carlsberg Glyptotek.

Here they are on coins!

Claudius, AD 41-54 and Agrippina II, AD 50-59.
Roman provincial Æ 20.2 mm, 5.81 g, 10 h.
Lydia, Thyatira, AD 50-54.
Obv: ΤΙ ΚΛΑYΔΙΟC CЄΒΑCΤΟC, bare head of Claudius right.
Rev: ΑΓΡΙΠΠΙΝΑΝ CЄΒΑCΤΗΝ ΘΥΑΤΙΡΗΝΟΙ, draped bust of Agrippina right.
Refs: Sear 507; RPC I 2380; BMC 22. 301, 57; SNG München 611; SNG von Aulock --; SNG Copenhagen --; Mionnet --; Wiczay --.

Caligula, AD 37-41.
Roman provincial Æ 20 mm, 6.74 g.
Peloponnese, Corinthia, Corinth, Ae. P. Vipsanius Agrippa and M. Bellius Proculus, duoviri, AD 37-38.
Obv: C CAESAR AVGVSTV, bare head right.
Rev: M BELLIO PROCVLO IIVIR / COR, Pegasus flying right.
Refs: RPC I 1173; Amandry (1988) XVII; BCD Corinth 405-6.

[Ryro]

It's uncanny! The notes, mouth and brow. 

Here's my latest Caligula coin with her on the reverse:

Gaius (Caligula)

AD 37-41. Æ Sestertius (33.5mm, 23.85 g, 7h). Rome mint. Struck AD 37-38. Laureate head left / Gaius' three sisters standing facing: Agrippina (as Securitas) leaning on column, holding cornucopia, and placing hand on Drusilla (as Concordia), holding patera and cornucopia; on right, Julia (as Fortuna) holding rudder and cornucopia. RIC I 33. Reddish-brown and light green patina, portrait defaced in antiquity. Fine. Purchased from CNG Jan 2023

Edited March 10, 2023 by Ryro

[Tejas]

Very nice, I think the damage to the face can plausibly explained as damnatio memoriae.

[ominus1]

...on coins in the Romans i've found this a lot,..just putting a bit of fem on it....i first noticed it on these types of Aurelius and Severina

[Valentinian]

Most ancient busts are found with the noses broken off and you can see in the OP that the busts have the noses restored. "Restored" means completely reconstructed in modern times to fit what the modern people think it should be like. Coins play a role because coins are attributed firmly and they have portraits with noses in profile. So, if scholars decide a bust is of Agrippina II (perhaps from the hairstyle, or perhaps because she is famous and an attribution to her would be more interesting than "First century noble woman") they can tell the restorer to add a nose that looks like the nose of Agrippina II seen on coins, making the bust look even more like Agrippina II than it did when it was found. 

I don't have a Roman imperial coin of Agrippina II to show, but I have this: 

Nero and Agrippina II, tetradrachm from Antioch. 24-22 mm. 14.17 grams.
Struck 56/57.  
Prier Nero 74. RPC 4175.

I hope someone will show us an imperial Roman coin with a bust of Agrippina II. 

 

[DLTcoins]

Antony and Cleo. I read somewhere that this was a Roman cultural norm having to do with the perception of powerful women (images courtesy CNG).

[Octavius]

 Two denarii of Caligula with his mother ,  and a denarius of Claudius with Caligula's sister.

To me Caligula looks more like his mother.