Athena must have been one of the most popular gods to represent in sculpture during antiquity, it's not uncommon that large museums have not one but several different pieces - the national museum in Athens have a room with only Athena statues, Glyptoteket in Copenhagen have at least four pieces and so on.
It is also very easy to recognize Athena, which of course helps us noticing her. She's normally the only armoured female god, she's wearing an Aegis (a piece of armour covering the upper torso, with a gorgons head in the center) and commonly a crested helmet. She is also often seen with a shield at her side and sometimes a snake or owl.
You might want to compare the picture above with the one of Athena Parthenos (a 2nd century ad copy) or a Hellenistic bronze Athena from Piraeus.