It isn’t uncommon for a big crossover to introduce a new character to a superhero universe. Generally, a new hero shows up, proves instrumental to saving the day, and may even get a new series of his or her own afterwards. Not always, but sometimes it does.
But then there’s Lady Quark and she doesn’t quite fit that pattern.
Lady Quark was introduced in the Crisis on Infinite Earths mega-crossover. The Anti-Monitor was destroying different Earths, and during an attack on Earth-6, poor witness Pariah decided, just this once, to try saving a life rather than just watching everyone die before moving on. He grabbed one Lady Quark. She was a ruler on that Earth alongside her husband Lord Volt and daughter Princess Fern. However, they died in front of her just as Pariah whisked her away.
Now, Lady Quark had some nuclear powers, flight, and a few other powers, but remember what I said about new characters being instrumental to saving the day? What was Lady Quark’s big contribution to defeat the Anti-Monitor?
She had no actual impact on the ending of the story.
Now, there were other characters introduced in the story that had bigger roles. Pariah, for one, was an early-warning system for the Anti-Monitor’s movements. Alexander Luthor, originally from Earth-3, was the chief scientist and inventor for the heroes. Harbinger was the agent of the Monitor who pulled a lot of people where they needed to be. And Lady Quark…was mostly just angry that her family was dead.
She didn’t get her own series afterwards either.
Mostly, she bounced around the universe, most prominently when she joined the intergalactic police force for hire, L.E.G.I.O.N.
But beyond that, she only really appears in Crisis sequels and the like. You can ask Jimmy about an appearance by an alternate version of her in Convergence, but he might not want to talk about it. I haven’t read that one, but it seems she did do some stuff with another Lord Volt there against Supergirl and maybe the Ambush Bug.
So, yeah. She didn’t really do a damn thing. And she still isn’t.