oh no...I imagine she has a huge tangle of strips and thread knots. I prewash reds since they thend to bleed the most. Anything else, if I think it may bleed, I'll take a snippet of the fabric and put it in a small glass of warm water, let it set for an hour and hold it up to see if there's any color in the water. It's perfectly ok to prewash in your kitchen sink to avoid the tangle monster that the washer creates. To answer your questions however, each strip needs to be pressed and trimmed of the threads then measured to judge any accuracy. She may end up with 1.5 inch strips. I would not prewash jelly rolls in a washing machine but by hand only.