OK so,
The ammo is 9mm pistol.
Hits an armadillo with enough force to kill it and ricochets.
Hits a fence and ricochets.
Travels 100 yards.
Goes through a back door.
Travels through the home.
Goes through a recliner.
Injures the woman in her back.
That is one magic bullet. I wish I new what brand it was.
The bullet should have been fracturing/deforming with each ricochet and penetration.
This would effect its ability to travel in a straight line and its ability to penetrate anything without being stopped.
I do not know and cannot speculate what really happened, but this story is very unlikely. That is just no how it works.
Maybe the distances are much closer than what is being described? Something is off here.