Some chinchillas are labelled as "bar runners" and that's exactly what they do - a habitual behavior where they just chew on bars and run back and forth along the cage bars.
It is a sign of boredom and can lead to high stress (which can form itself into other habits as fur chewing), that is why outside-the-cage playtime is so important. They are captive animals and they always need to be mentally stimulated. Constantly introducing new toys and re-arranging them can limit this behavior while they are in the cage - but still a couple hours of exercise outside the cage will help prevent these behaviors.
If you go to a zoo, the zoo keepers will tell you that a few of their animals have developed habitual behaviors in their habitats which may involve pacing, OCD movement of objects, etc - these are all negative qualities to have. Captive animals need a lot of mental stimulation!
If she still hasn't pooped or you are concerned that she may be constipated - try giving her 1 raisin. I NEVER promote giving fruits as treats but raisins have been shown to be a laxative and most breeders will recommend this. If there is still nothing, you may have to see a vet.