Who is Sophia?

""And the Sophia of the Epinoia, being an aeon, conceived a thought from herself and the conception of the invisible Spirit and foreknowledge. She wanted to bring forth a likeness out of herself without the consent of the Spirit, - he had not approved - and without her consort, and without his consideration. And though the person of her maleness had not approved, and she had not found her agreement, and she had thought without the consent of the Spirit and the knowledge of her agreement, (yet) she brought forth. And because of the invincible power which is in her, her thought did not remain idle, and something came out of her which was imperfect and different from her appearance, because she had created it without her consort. And it was dissimilar to the likeness of its mother, for it has another form.

"And when she saw (the consequences of) her desire, it changed into a form of a lion-faced serpent. And its eyes were like lightning fires which flash. She cast it away from her, outside that place, that no one of the immortal ones might see it, for she had created it in ignorance. And she surrounded it with a luminous cloud, and she placed a throne in the middle of the cloud that no one might see it except the holy Spirit who is called the mother of the living. And she called his name Yaltabaoth."
http://www.gnosis.org/naghamm/apocjn.html

"“When he said this, he sinned against all. And a voice came from above the realm of absolute power, saying, ‘You are wrong, Samael,’ that is, god of the blind.

“And he said, ‘If any other thing exists before me, let it become visible to me!’ Immediately Sophia pointed her finger and introduced light into matter, and she pursued it down to the region of chaos. And she returned up to her light. Once again darkness returned to matter.

“This ruler, by being androgynous, made himself a vast realm, an endless precinct. And he contemplated creating offspring for himself, and created seven offspring, androgynous like their parent.

“And he said to his offspring, ‘I am the god of all.’

“Zoe the daughter of Pistis Sophia shouted, saying to him, ‘You are wrong, Sakla’ (for which the alternate name is Yaldabaoth). She breathed into his face, and her breath became a fiery angel for her; and that angel bound Yaldabaoth and cast him down into Tartaros, at the bottom of the abyss.

“Now, when his offspring Sabaoth saw the strength of that angel, he repented and condemned his father and his mother matter.

“He loathed her, but he sang songs of praise up to Sophia and her daughter Zoe"
http://www.gnosis.org/naghamm/Hypostas-Barnstone.html

"After the natural structure of the immortal beings had completely developed out of the infinite, a likeness then emanated from Pistis (Faith); it is called Sophia (Wisdom). It exercised volition and became a product resembling the primeval light. And immediately her will manifested itself as a likeness of heaven, having an unimaginable magnitude; it was between the immortal beings and those things that came into being after them, like [...]: she (Sophia) functioned as a veil dividing mankind from the things above."
http://www.gnosis.org/naghamm/origin.html