Hera (Ήρα in Ancient Greek) is the goddess of women and marriage. Her husband is Zeus and she is therefore the Queen of the Gods. She is the youngest daughter of Rhea and Kronos, and was also swallowed by her father with all of her other siblings except Zeus. Her roman counterpart is Juno.
Hera spent her childhood in her father's stomach. Zeus rescued her, and after the war with the Titans ended she married him and became the Queen of the Gods. After accepting Zeus, Gaia gave Hera the golden apples of immortality as a wedding gift, which she placed in her garden at the western edge of the world. Hera employed the Hesperides, daughters of Atlas, to guard the tree, but as the nymphs would occasionally pluck from the tree themselves, she also placed a one hundred headed dragon named Ladon there as well. This orchard was later named The Garden of Hesperides.
Over time, Zeus was very unfaithful to her, and had many children by mortal women. This understandably frustrated Hera to no end, and she devoted most of her time to keeping Zeus in sight, as well as making the lives of the mistresses and illegitimate children miserable.
Her hatred is most evident in the story of Hercules, whom Hera tried to kill repetitively, and who later ended up as her son-in-law by her daughter Hebe.
Hera gave birth to Hephaestus, and when she saw his unsightly appearance, she threw him from Olympus, crippling him forever. This act of cruelty haunted Hephaestus for life, and was a factor in his bitterness with life and the fact that he preferred to work away from his family.
Hera is noted to blame this on her husband Zeus. Later in life, Hephaestus gained revenge against Hera for rejecting him by making her a magical throne which, when she sat on it, did not allow her to leave. The other gods begged Hephaestus to return to Olympus to let her go, but he repeatedly refused. Dionysus got him drunk and took him back to Olympus on the back of a mule. Hephaestus released Hera after being given Aphrodite as his wife.
Hera claimed the golden apple that her daughter Eris threw, with the words 'for the fairest' written on it. Paris was chosen by Zeus to pick who was the fairest. She lost to Aphrodite, because of the bribe she had offered Paris. Hera then engaged along with Athena in revenge against Paris for rejecting them which started the Trojan War.
Hera has long chocolate brown hair woven into a braid with gold ribbons, and wears a simple white dress that ripples like oil on water when she moves. She is very beautiful, and looks like 'an average Mom,' according to Percy. Hera is supposedly a very intimidating sight with 'eyes glazed with power.' When first appearing to Percy and his party, he is unsure if he is any better off with Hera then with Janus.
Hera can change is appearance and turn into her Roman counterpart, Juno. As Juno, she becomes more disciplined, warlike, and militaristic. She wears a black hooded robe, with a goatskin cloak over her shoulders.
Hera seems to be a mothering type, which is likely caused by her status as the goddess of women, marriage, and children, but is seen to be very jealous. When cross, even Zeus can be afraid of his wife. She also likes only 'perfect' children. She didn't care anything for Hephaestus because he wasn't her idea of the kind of son she wanted. Hera carries great loathing for the illegitimate children and mistresses of Zeus, for good reason. She is seen as often aware of Zeus's various affairs, many times thwarting them and tricking him into getting what she wants. Though perhaps her anger should be more keyed toward her husband, Hera seems to gain revenge by punishing the women involved as well as the children that result from his affairs. As goddess of marriage, Hera is "used to perseverance," and is always reconciled with Zeus despite his frequent infidelity. She expresses sadness over the loss of faith seen in the minor gods, and reminds demigod always look at the big picture.
It is unknown what kind of supernatural powers Hera possesses. In the Labyrinth she makes food appear out of thin air, like Dionysus can. As queen of the gods, she seems to wield authority over the entire Earth, and was able to offer Paris kingship over all mortal countries if he chose her as the most beautiful goddess instead of Athena or Aphrodite. She also caused all land masses to shun Leto while she was in labor with two of Zeus's illegitimate children, Apollo and Artemis. She is the goddess of marriage, and might have the ability to bless marriages, or curse them if she is crossed. She is the goddess of motherhood, and might be able to affect fertility. Hera presumably possesses the standard powers of a god.