The Summers' have an extensive and Tangled Family Tree. Every family member can kick ass: they are poster children for eugenics. Daddy was (is) a space pirate. His three (confirmed) sons are two superhero team leaders and a supervillain who conquered his own space empire.
His grandchildren include (but, since this is the Summers family, may not be limited to) a world-conquering time-travelling messiah so powerful he was able to fight the Silver Surfer to a standstill while simultaneously repairing all the collateral damage from their confrontation, a time-travelling celestial avatar who fought Galactus to a standstill, a trans-dimensional alternate universe equivalent of the previous messiah of near Cosmic Entity levels of power, a world-class supervillain and the daughter of Emma Frost. Known spouses/girlfriends include another celestial avatar, the daughter of the Big Bad, a supremely badass mercenary, an insane galactic warlord, a Cat Girl space pirate, Emma Frost, and Deadpool (sortof).
X-Men (2019) particularly leans into this, since for once the entire gang is alive and on the same side. This◊ cover of the first issue shows the entire Summers family (and Wolverine) in their new home on the moon.
Also, the House of M, although just who counts (*coughmagicchildrencough* ) is still in flux, and they're just as likely to fight each other than you.
Spider-Man: The Parker family. Obviously, there's Peter Parker himself but it doesn't stop there:
Peter's uncle Ben fought in World War II and told his nephew stories of Captain America (it's not certain if he met Cap personally or just knew of him). There is also the pre-Spidey story in which Ben and Peter escaped from a giant monster.
His Aunt May once poisoned the Chameleon and was gutsy enough to swipe Wolverine's cigar and tell him to smoke outside.
His wife Mary Jane was no slouch in the badass department either since she once handled a hostage crisis, another time beat up the Chameleon with a baseball bat, and still another time cold-cocked sleazy Daily Bugle reporter Nick Katzenburg.
In yet another alternate future, (Earth X timeline), Peter has another version of May who is no less badass and still takes up superheroing.
In the alternate universe series The Amazing Spider-Man: Renew Your Vows, Mary Jane dons a special costume that allows her to use Spidey's powers, taking the codename "Spinneret" and their super-powered daughter in this universe, Annie May, is given the codename "Spiderling" (despite the girl begging for "Spider-Girl")
The Incredible Hulk: The Banner family. Including, but not limited to, Bruce Banner/The Hulk, his cousin/stand-in sister She-Hulk/Jennifer Walters; wife Red She-Hulk/Betty Ross Banner; children Skaar, Hiro-Kala, and Lyra; and father-in-law Red Hulk/Thunderbolt Ross.
At one point they formed an official team along with close family friends Rick Jones/A-Bomb and Korg.
It's also been heavily implied, though never confirmed, that Carmilla Black, the current Scorpion and daughter of Monica Rappaccini (the head of AIM), is also Bruce's daughter.
In addition, his past serious committed relationships Jarella and Caiera were warrior-women (as was Thundra, but that was not even an affair). Umar the Unrelenting, queen of the Dark Dimension, made him her consort on two occasions. He also had a college fling with the AIM Scientist Supreme Monica Rappaccini, which means that he and M.O.D.O.K. were romantic rivals...
Betty also has a daughter, the benevolent mystical entity Daydream, due to being raped by Nightmare, but although the demon keeps up his creepy "children fathered through rape" tendency with Trauma and Dreamqueen, nobody has had an interest in reintroducing her yet.
Captain America: The Carter lineage most definitely qualifies. While Peggy Carter fought with the French Resistance in World War II, her niece Sharon continues the kick-assery in the modern day, often teaming with Captain America to fight bad guys. In the Marvel Comics 2 continuity, there's also Sharon's niece, Shannon Carter, who becomes "American Dream", a proud and worthy successor to Cap's shield.
In the 100th AnniversaryGuardians of the Galaxy special, Rocket Raccoon fights alongside his 3 half raccoon - half…. some alien, children (although he insists that they're his nephews). The triplets are all badass adorable personified.
The Koenig brothers in Agents of S.H.I.E.L.D.. While they're all a little... odd, all of them are high-ranking S.H.I.E.L.D. agents, trusted by Nick Fury to guard S.H.I.E.L.D.'s top-secret bases — bases so secret that most S.H.I.E.L.D. agents weren't even made aware of their existence.
Daisy Johnson's mother was the immortal leader of Earth's Inhumans, her father had the second worst temper in the MCU, and her half-sister's power was the key to saving Earth. She also considers all of Team Coulson to be her extended family.
The royal family of Atalan all have powers and are trained to use them to fight, except for Maximus, who outsmarted them all.
All of the PRIDE families in Runaways (2017) can be considered this between the mostly Badass Normal supervillain parents and their more heroic offspring.
The Maximoff family in WandaVision, with Action Mom Wanda, Action Dad Vision, and their superpowered twin boys Billy and Tommy. Wanda also had a brother named Pietro who was just as badass with Super-Speed. This is especially exemplified in the ninth episode during the battle with SWORD and Big Bad Agatha Harkness.
Echo (2024): Not only Maya here (who is as usual a very skilled fighter) but several of her Choctaw relatives along with her turn out to be badasses. This includes two female ancestors of hers we see, an athlete and later a police officer. Living relatives of hers include her uncle, a gangster like her, while her grandmother and cousins briefly turn into them too fighting Fisk's men in the last episode.
◊ cover of the first issue shows the entire Summers family (and Wolverine) in their new home on the moon.
