According to the urbane retelling of myth in Ovid’s Metamorphoses, for a long time, a nymph named Echo had the job of distracting Hera from Zeus’ affairs by leading her away and flattering her. When Hera discovered the deception, she cursed Echo to only repeat the words of others (hence our modern word “echo”).
Leto and Artemis/Apollo
When Hera discovered that Leto was pregnant and that Zeus was the father, she banned Leto from giving birth on “terra-firma”, or the mainland, or any island at sea. Leto found the floating island of Delos, which was neither mainland nor a real island, and Leto was able to give birth to her children on the island. As a gesture of gratitude, Delos was secured with four pillars. The island later became sacred to Apollo. Alternatively, Hera kidnapped Eileithyia, the Goddess of Childbirth, to prevent Leto from going into labor. The other gods forced Hera to let her go. Either way, Artemis was born first and then assisted with the birth of Apollo. Some versions say Artemis helped her mother give birth to Apollo for nine days. Another variation states that Artemis was born one day before Apollo, on the island of Ortygia and that she helped Leto cross the sea to Delos the next day to give birth to Apollo.
Semele and Dionysus
When Hera learned that Semele, daughter of Cadmus King of Thebes, was pregnant by Zeus, she disguised herself as Semele’s nurse and persuaded the princess to insist that Zeus show himself to her in his true form. When he was compelled to do so, his thunder and lightning blasted her. Zeus took the child and completed its gestation sewn into his own thigh. Another variation is when Hera persuades Semele to force Zeus to show himself in his real form. Unfortunately, he must do what the princess wants, having sworn by Styx. In another version, Dionysus was originally the son of Zeus by either Demeter or Persephone. Hera sent her Titans to rip the baby apart, from which he was called Zagreus (“Torn in Pieces”). Zeus rescued the heart and gave it to Semele to impregnate her; or, the heart was saved, variously, by Athena, Rhea, or Demeter. Zeus used the heart to recreate Dionysus and implant him in the womb of Semele—hence Dionysus became known as “the twice-born”. Certain versions imply that Zeus gave Semele the heart to eat to impregnate her. Hera tricked Semele into asking Zeus to show his true form, which killed her. But Dionysus managed to rescue her from the underworld and have her live on Mount Olympus.
Hera almost caught Zeus with a mistress named Io, a fate avoided by Zeus turning Io into a beautiful white heifer. However, Hera was not completely fooled and demanded that Zeus give her the heifer as a present.
Once Io was given to Hera, she placed her in the charge of Argus to keep her separated from Zeus. Zeus then commanded Hermes to kill Argus, which he did by lulling all one hundred eyes to sleep. In Ovid’s interpolation, when Hera learned of Argus’ death, she took his eyes and placed them in the plumage of the peacock, accounting for the eye pattern in its tail. Hera then sent a gadfly (Greek oistros, compare oestrus)) to sting Io as she wandered the earth. Eventually Io was driven to the ends of the earth, which the Romans believed to be Egypt, where she became a priestess of the Egyptian goddess, Isis.
Lamia was a queen of Libya, whom Zeus loved. Hera turned her into a monster and murdered their children. Or, alternately, she killed Lamia’s children and the grief turned her into a monster. Lamia was cursed with the inability to close her eyes so that she would always obsess over the image of her dead children. Zeus gave her the gift to be able to take her eyes out to rest, and then put them back in. Lamia was envious of other mothers and ate their children.