Why? It made zero sense that she didn't disappeared earlier.
No Mutants Allowed
Walpknut
R.Graves
BecauSe. . . If jack was sent to the future by aku, then the past 50 years DID happen and therefore ashi exists. Not only that but ashi MUST exist as without her it would be impossible for jack to get back to the past.
R.Graves
So if time was a straight line, it is no longer. Those 50 years go forward and then loop back around into the original timeline and as a result both timelines happened.
R.Graves
But within the same line. And so it makes no sense for ashi to disappear.
R.Graves
It's your basic temporal causality loop. Like, in terminator. Or TNG