Or dads, for that matter. The gold standard for comic book dads is that the kid disappears as a baby (or is never even known to exist in the first place) and then doesn't show up in the 'dad's' life until they are a teenager or adult, so the super-hero dad never actually has to *parent.*
Happens to everyone. Batman, Cyclops, even Superman now has a grown-up kid and missed half of his childhood. (Granted, they are all just following in the footsteps of their own parents. They all lost their dads early, to death or space-piracy, because comic book characters don't just not get to be parents, but they don't get to *have* parents either!)
Jean's just a riot. She's got all these AU kids running around, Rachel, Cable, Nate, and she's not actually given birth to any of them. Hell of a way to avoid stretch marks...
I actually kind of like those rare super-characters who have utterly normal parental situations, like Bobby or Hank. Everyone else? Dead / absent parents. Scott, Jean, Ororo, Logan, Piotr, Sean, Warren, etc.
And then there's the ones I don't even know. Did Jubilee or Rictor ever even have parents? Betsy and Brian? Rogue and Remy? I mean, sure, they must have come from somewhere, but for all their parents have mattered to their storylines over the last few decades, they might as well have been hatched from eggs.