No. Metis, her mother, was not married to Zeus. Athena can't really have step siblings if her mother was never married.
Yes athena is step sister and half sister ofartemis
Yes she is she is Apollos and Artemis's step sister
No, but Apollo and Artemis are step-brothers
who are Athena's siblings
Depending on the account you read, Athena was either Hera's step-daughter or her sister, and although in the step-daughter account, Hera was very angry at Zeus for having a child without her, the anger was directed at Zeus (or in some accounts his mistress), and not at Athena herself.
she is his half sister
No. Athena was an only child.
No, that is Athena's sister Artemis.
Apollo's twin sister is Artemis. Athena is their half sister.
Athena was aphrodite's sister
no Athena was Zeus's daughter
His half sister is Athena, the goddess of wisdom