In many myths Athena is described as "owl-eyed" and this is how I imagine her as a girl:
This is the story of her quite remarkable birth.
When Zeus had defeated the titans and became the ruler of Olympus, he married his first wife: Metis, the goddess of wisdom. Though she was a good wife and a true equal of Zeus, it was foretold by Gaia that she would be the one who could bear a child strong enough to defeat Zeus himself. Zeus wasn't too happy with this news, so to prevent Metis from bringing forth this child, he tricked her into changing herself into a fly and swallowed her.
Metis, however, was already pregnant with Athena and, while inside Zeus, she began to forge an armour for her daughter. The hammering caused Zeus such a headache, that he asked Hephaistos to split open his head. Out of the crack sprang Athena, the new goddess of wisdom. Though she is also the goddess of warefare, strength and strategy, a woman could obviously never overthrow her father and Zeus' reign over the gods and mankind was secure.
An additional advantage of swallowing Metis, was that Zeus now had Wisdom inside of him. Therefore he became a much wiser god and he could go on to marry his sister Hera and have many affairs with mortal girls.
Athena, very unlike her father, vowed to remain a virgin. She does have a very cute little owl called after her, aptly named "Little Owl" or Athene noctua.