In short, for the Greeks the concept of a "female" deity was very different than the concept of a female human; it wasn't a one-to-one comparison. More can be said about gender perceptions in ancient Greek mythology and society if anyone wishes to add further, but in the meantime, here are some older answers you may enjoy:

• Why was one of the Greek Gods of war female, despite Hellenistic culture's patriarchal roots? by /u/JoshoBrouwers.
• How come some of the most important Greek gods were women (Athena, Artemis, Demeter) yet their society remained so strictly patriarchal? by /u/mythoplokos, which also led to a follow-up in:
• Several ancient polytheistic religions (like in Greece or Egypt) included female deities responsible for areas, that were traditionally men's jobs in the respective cultures (warfare, hunting, etc). How did deities like Athena for instance come to be? by /u/UndercoverClassicist.