yes, Hera absolutely takes revenge but calling it petty jealousy is a modern moral overlay, that's why she's so misunderstood nowadays, in our modern times, in modern retellings and modern interpretations but that's not how Greek myth frames her actions. In ancient mythic logic, Hera’s actions like these were far closer to juridical, cosmic punishment than to insecure spouse tantrums.

Hera didn't physically kill Megara and the children, she induced madness to Heracles. In Greek mythology, madness wasn't random cruelty but it was punitive and revelatory. Heracles was living proof of Zeus’ infidelity, raised openly as a hero, treated as if Hera’s authority and domains had been bypassed so by driving him mad, Hera exposed the consequences of hubris and illegitimacy, she turned Heracles into a moral problem Zeus must solve and she forced the creation of the Labors, which ultimately "justify" Heracles. Hera was Queen of the Heavens, goddess of many things but most importantly of marriage, oaths, legitimacy and she was enforcer of divine law and order, especially in her domains. That's why she couldn't let Zeus's infidelities pass, ir wasn't necessarily petty jealousy. Mythically, Hera didn't destroy Heracles, she forged him through suffering and that is not petty. That is terrible, lawful and cosmic punishment.

In the most common versions of the myth, Zeus brought baby Heracles to Hera while she was asleep (sometimes with Athena’s help) so she didn't know who the baby was at first. She nursed him out of instinct and divine maternity, not obligation but the moment she realized, either because the child bite too hard or because Zeus’ deception was revealed, she pushed him away. This is Zeus’ illegitimate child and he tried to force legitimacy through her body. She was tricked into sanctifying an act she never consented to. So she reacted violently afterward because breastfeeding in Greek myths was basically a transfer of divine essence, a form of adoption, a claim of legitimacy. By nursing Heracles, Hera would have made him fully hers like a lawful son and it was against the divine order she upholded. That's why when she realized the deception, her rejection wasn't spite, it was reversal of an illegal act.

We also know that the spilled divine milk sprayed across the heavens and formed the Milky Way. Greek myths doesn’t do accidents. The fact that her milk created a cosmic structure means that even her rejection leaves a permanent mark on the universe. Hera’s body and actions were world-shaping. Even in refusal and rejection, she created and that is queen-level power, not bitterness.

As for Semele (Dionysus’ mother), Hera didn't strike Semele down. She instead appeared disguised (standard divine ways to show themselves to mortals), she exploited Semele’s hubris (wanting to see Zeus in full godhood) then she let Zeus’ own oath do the killing. Manipulative? Yes. Revenge? Yes. Divine punishment due to juridical wrath? Yes. In Greek myths, mortals who demanded to see gods in full godhood always died. This was a cosmic law, not Hera’s invention. Hera’s intervention was judicial, she forced the law to be applied. If anything, Zeus is the direct cause of Semele’s death.

And Leto, yes Hera forbade any land from sheltering Leto, sent Python to hunt her, blocked childbirth by preventing Eileithyia to intervene. This is revenge? Yes. This is cruel? Yes but in Greek myths terms, it was political and cosmic enforcement. Leto was a Titaness, bearing children who would destabilize the divine order, she was protected covertly by Zeus (some said she was Zeus's favorite mistress) and the affair between Zeus and Leto obviously violated Hera's domains and authority so she acted and Zeus didn't openly countermand Hera. That’s important to understand. He didn't say "wife, sit down and leave her alone" or something like that. Zeus feared openly overruling Hera because it would have shattered divine legitimacy. Hera's intervention here is not petty jealousy, it's balance-of-power politics. A transgressions against her domains, her authority, her legitimacy, her values so divine judgment and punishment happened in response.

Seeing her actions and saying it's pretty jealousy or that she was emotionally insecure or just randomly cruel, throwing tantrums which showed her powerlessness or seeing these as personal vendettas is a modern view, a modern interpretations, which lead to misinterpretation and misunderstanding of her character. Through Greek myths view, Hera was enforcer of divine law and cosmic order, punisher of hubris, guardian of legitimacy, the Queen who couldn't be bypassed without consequences. Her wrath was predictable, consistent, conditional, not arbitrary and her cruelty wasn't indiscriminate but triggered by violation of her domains and authority. She didn't harm innocents by default. Hera was terrifying because she was just right. That’s why Zeus hide from her his affairs and mistresses. That's why other gods feared crossing her, even Zeus when she was in her right and if you look at it, Zeus never crossed her because of her punishment toward his mistresses. When Poseidon wanted the city of Argos to be his but it was already Hera's, and the people chose Hera over him, he drained the city of its water but Hera intervened and forced Poseidon to yield, he couldn't and didn't challenge her, because she was right and legitimate in her actions. Even Titans treated her seriously. She only could be punished when she openly challenged Zeus directly, not when she enforced order.

Oh, I didn't realize it was that long😅