I never really thought about it. She looks adorable. Does she make cameos as an adult or is she dead in the present story which is why the triplets live with their uncle?
Varies on the author but it is extremely rare to even be brought up. What's cool about Duck stories is that every single one is pretty much standalone but each writer is able to build their own canon around it.
Carl Barks created pretty much every character but he didn't give a shit about what was canon or not. Don Rosa is a Barks superfan so he made sense of what Barks had done and had his stories set in that canon. Barks didn't give a shit about backstories but every once in a while he hinted at something about Scrooge's past, could be something like "When I was a kid I used to shine shoes" and "I once met a zombie" and Rosa wrote down all of this and made The Life & Times of Scrooge McDuck around it.
But other writers may not care about it so those stories will have their own supporting cast, backstories, etc. So some may have the mother as missing, dead or whatever. I remember one Italian writer had her as an astronaut that had gone missing in space. Others may have her as just wanting some time alone.
To give a sense of how varied canon can be, there are a lot of great stories about Mickey Mouse as a hardboiled detective in noir stories. Completely different supporting cast.
Or Donald as a superhero, in these stories Donald has a completely new supporting cast. No triplets, Scrooge, etc.
I've read thousands upon thousands of these comics and they are enormous all over the world except for America because Disney has moronic rules about what is and what's not allowed to do with these characters but they don't give a shit, or didn't used to, about what's done with them outside of America which is how we ended up with all these great comics with great writing made by people who actually love the characters. So in America, Mickey Mouse will teach you how to spell and in Europe he'll solve murders.
Fan demand for this to be printed in America has been huge for decades and Disney doesn't give a shit. The few times they've actually printed something, it immediately sells out. And they keep screwing over the writers and artists, especially Rosa.
