The number of capes you know are closely associated with your family can be counted on one hand. There are almost certainly dozens more, but you've never really cared enough to meet or learn about them aside from their occasional mention in stories. Celes has.
Serious Heroes
Overseer: Nicknamed "Big Brother," Overseer was a Researcher active approximately two decades ago. He specialized in cheap flying drones and the mass production thereof.
Overseer is best known for trying to establish a nationwide surveillance net in order to eliminate crime and prevent villains from freely committing crimes. He'd intended to keep the movement secret, but the net was still incomplete when an unknown (presumed powered) individual broke into his HQ and copied his records. Nine days later, a two-hour video titled "Best of Overseer: Highlight Wheel (raw data in description)" was released onto the Internet. It got taken down in very short order due to age-inappropriate content; apparently, the thief had decided to prioritize displaying the most blatant invasions of privacy he could find.
When it was put up on a different site, one which permitted such content, Dreadnought's third-generation AI assistant "Stacy" released a virus intended to target and delete the video on any computer connected to the Internet. It is almost certain that multiple copies survived in offline storage, but those possessing them did not try to publicly re-release the content.
Regardless, Overseer was soon bombarded by a slew of lawsuits. He subsequently went into hiding and continued trying to, as he put it, "stop crime." He was somewhat successful in the areas he targeted, but his expansions were frequently answered by attacks from any capes living in the region, hero or villain.
After two years, an anonymous individual stepped forward and claimed Overseer had been convinced to retire. This came soon after Overseer's reveal of Cyclone's civilian identity, a villainous aerokinetic known for multiple high-profile abductions. Overseer himself publicly apologized, claimed he'd seen the error of his ways, and vanished from public view.
Several Minds have since stated that Overseer was both terrified and lying through his teeth. Other Builder-type capes with similar specialties have since confirmed that he still lives.
One could argue that Overseer's overall net contribution to society was positive, even if both villains and heroes opposed him. After all, your parents met and bonded over opposing his expansion.
Null: One of the few power nullifiers on the planet, Null is able to negate the powers of every cape within twenty yards. Aside from Progenitor, he is the only cape you know of who is also capable of negating the effects of those powers on the world itself. Rocks thrown solely with telekinesis would abruptly stop, cyrokinesis-caused ice would vanish, every part of a pyrokinesis-caused fire would be snuffed out, and so on.
Null's ability to undo such effects has been the source of many headaches for those who wish to puzzle out how his ability is supposed to work. It doesn't help that his ability is incapable of undoing damage already inflicted by a power-caused effect. Like most power nullifiers, he frequently commissioned new equipment from Builders and made a living off hunting down capes with bounties on their heads.
As for Null's relationship with your family? Thanks to the aura of fear, it's near impossible for Father to find people willing to stay near him. Yes, he can suppress the aura while in the human form Mom made him, but he claims it's unreasonably uncomfortable. Null has no such problems.
Aside from that, you don't know Null very well. You know he took up a teaching position at Paragon a few years back, but that little factoid didn't really make any difference on your decision-making process. On the one hand, family friend. On the other, that very relationship would be likely to encourage him to work you even harder and hold you to higher standards. No, thank you.
Non-combat Hero(es)
Intern: A mid-grade healer, Intern is excellent at dealing with most injuries, but incapable of effectively eliminating healing-resistant diseases. Like many such healers, she is forbidden from even trying outside of major emergencies. Incomplete removal is how healing-resistant diseases were created in the first place.
Your father frequently calls her in when civilians have been caught up during a cape fight. You've met her a few times and are relatively ambivalent; the middle-aged woman seems to have an eternal aura of exhaustion and stress, even when she's laughing and enjoying herself. She's not completely immune to Father's aura of fear, but she claims she can just constantly heal her brain to remove the effects.
You don't know why Intern chose that particular name. You don't have a good enough grip on her sense of humor to figure it out, either.
Neutral
Retcon: A presumed reality warper capable of "removing" the effects of one event up to two minutes in duration. Can only target events 2-26 hours in the past. Participants will still remember the original timeline and may find themselves in better or worse condition than they were previously. Most wounds caused by an event could be fixed, but Retcon cannot undo death. This apparently-arbitrary restriction has confused many and helped contribute to the theory of reality warping instead of temporal manipulation.
You honestly can't do a better job of explaining it; that's basically all your mother told you. Since her summaries are usually significantly better, you're guessing she's as unsure as you are.
Regardless, Retcon seldom gets involved in the cape scene, only using his abilities when he's paid obscene sums of money to do so. Your mother apparently met him when they were both going to college and they've stayed in infrequent contact since then. You've never met him yourself.
Lives in New York.