I've had dogs, including one of my current dogs, who always walk and poop. Makes picking up a bit more challenging, but it's perfectly normal for them. My current "walking pooper" is almost 13 and I think he poop walks even more than he used to (spreading the deposits over a larger area). I've assumed it's arthritis related.
As long as she's pooping w/o straining, I don't think I'd worry about it too much. I think a lessened amount of stool would be relatively normal on a diet of canned food/baby food.