"I managed to find out about the rocket before Scrooge wanted to tell me. And... I wanted to take it for a ride. In that moment, I was only thinking of myself. I'd never ridden one before, but I'm a pilot. I assumed it would be like flying a plane, and I'd be back before it mattered. I left behind a note, and went into the rocket, taking off."

A long sigh, turning her head away.

"... But in space, there are a lot of things you can't prepare for. I didn't even think about what might happen out there. There was... an asteroid field. A ton of rocks that I couldn't dodge. I tried to turn back, tried to get away, but... I couldn't. I wound up crashing on the moon. The rocket ship itself was destroyed... and one of the parts landed on my leg."

She wouldn't tell the grisly details of having to give herself an amputation, but she left it vague enough to imply it.