Did Athena actually have a mother?

Metis was her mother. Her father was Zeus.
Athena's mother was Metis according to some myths. Zeus had sex with her but was scared of the consequences. He swallowed her alive, but it was too late because Metis had already conceived. Eventually Zeus experience a terrible pain; Prometheus, Hephaestus, Hermes, or Palaemon (it depends what version of the myth you read) hammered Zeus' head with a labrys (a double headed axe). Athena then burst out of Zeus' head fully grown and clothed in battle armor.

(Paraphrased from Wikipedia)
Athena's mother is Metis, the Titanness of wisdom.
She doesn't have one. She was born from Zeus' head.