Definitely a place like JoAnn's or another fabric shop where they are having a sale. She can go either online or to the store and sign up for their mailing list. JoAnn's usually has at least 1 50% off coupon in their monthly fliers and definitely 40%. Sometimes, at least in our local paper, there is an insert from there with coupons in it. Also, maybe she can check a place like Goodwill or Salvation Army.
Even check online for deals - just compare shipping vs. buying locally.