Depends on which story is used. One would say she is her aunt as she was born from the discarded testicles of Uranus. Home calls her the daughter of Zeus and Dione which means she is a niece to Hera. The more common choice is the first.
Hera was one of the six original gods and goddesses, the children of the Titans King Cronos and Queen Rhea. Gaea[Mother Earth] and Ouranus[Father Heaven] are the grandparents of Hera. Gaea and Ouranus gave birth to the titans including Cronos and Rhea. Her siblings were Zeus, Poseidon, Hades, Demeter, and Hestia. She was also Zeus' husband (the gods seemed to have a thing for marrying siblings, esp. Zeus). The rest of the Gods are the 6 original Gods/Goddesses descendants. So in sense, Hera is related to ALL of the Gods by blood.
There are 13 main God's, This list provides their responsibilities and their relations to Hera:
Zeus: Lord of Sky [Hera's husband]
Hera: Protector of Marriage, Protector of Heroes
Poseidon: Ruler of Sea [Hera's Brother]
Hades: Ruler of Underworld; God of Wealth, God of Dead [Hera's Brother]
Hestia: Goddess of the Hearth, [Hera's Sister]
Demeter: Goddess of Agriculture and Harvest, [Hera's Sister]
Pallas Athena: Goddess of City, Battle goddess, Protector of Civilized Life, Protector of handicrafts, Protector of agriculture [Daughter of Zeus(From Head) so Hera's adopted daughter or niece]
Phoebus Apollo: Master Musician, Lord of Silver Bow, Archer God, Far-Shooter, The Healer, God of Light, God of Truth [Son of Zeus and Leto, Artemis's Twin Brother, Hera's nephew]
Artemis: Lady of Wild Things, Huntsman-in-Chief, Protector of Dewy Youth, 'Moon', Refered to as Hecate: 3 forms - Selene in Sky. Artemis on Earth. Hecate in lower world. Hecate: Goddess of the Dark Moon, Deeds of Darkness, Goddess of the Crossways. [Daughter of Zeus and Leto, Apollo's Twin sister, Hera's niece]
Aphrodite: Goddess of Love and Beauty, [Daughter of Zeus and Dione; Later said to have sprung from sea, Hera's niece]
Hermes: Messenger God, Master Thief, God of Commerce and Market, Protector of Traders, [Son of Zeus and Maia, Hera's nephew]
Ares: God of War, [Hera's son]
Hephaestus: God of Fire, Worker of the Immortals - Their Armorer and Smith, God of Ceremony, Protector of Smiths [Son of Hera]
Athena is the niece of Hera; Zeus is the brother of Hera.
Hera was honoured by sacrificed peacocks
Hera sent Athena to talk to Achilles, she asked him to put down his sword. He said he had to obey the goddesses.
No, Athena turned Arachne into a spider after she hanged herself.
Yes when Hera, Posiden, and Athena betrayed Zeus he was mad and first attacked Hera, then his son Apollo, and final Posiden zeuses brother.For their punisment he made them build the wall of troy
Hera's son Ares is also a son of Zeus. Hephaestus, Hera's other son, is sometimes said to be a son of Zeus, but he is also sometimes considered to be a son of Hera alone. Hera bore Hephaestus alone because she was jealous of Zeus, who bore Athena on his own.
Paris was asked to judge the beauty of Hera, Aphrodite, and Athena.
yes
Athena and Hera
Athena, Hera
yes
Hera was honoured by sacrificed peacocks
Athena the Greek god was the daughter of Zeus and hera.
Athena's aunts [Zeus' side]: Hera, Hestia and Demeter.
yes they are
Hera, Hestia and Demeter.
Artemis, Athena, Aphrodite, Amphitrite
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.