I can see both points presented here in this thread. We should learn the correct way of doing it, that is why we are taking a class. However, the instruction could have been a tad more tactful in how she did things. Certainly your sister does not want to be discouraged, but I assume she wants to learn how to quilt and do it the right way. Is she using her own machine? If so, the teacher should have taken the time to show her how to achieve the 1/4 seam on it, using tape or something to help guide her. I think that having to rip out the seams is a bit much, but perhaps the outcome requires the seams to be correct. In any case there are two ways to look at this. Which is right, I am not sure, but I would want to learn to do it correctly the first time, otherwise it would be easy to just say oh well it does not matter, and then in a more complicated quilt it might make all the difference in the world.