She did have a point though, if you want quality fabric don't buy it at walmart. You also should realise as an employee she has no personal investment in the fabric or the quality of the fabric. She's just as much at the mercy of walmart as you are.
Most manufacturers are at the point with walmart where they must start cutting the quality of thier products to the bone. They've already cut labor costs by offshoring their manufacturing facilities. Expect poorer quality every day.