2006 chevrolet Equinox using oil

This is totally normal behavior, if you mean a quart every 4000!!! miles, not 400. If the car was broken in perfectly, it MIGHT not need any oil betwen changes. There are cars that consume 1 quart every 4000 from the day they are new.

In your daughter’s case maybe you could tell us more about the history of the car; did she buy it used, and what maintenance has been done to date.