Go to Sue Beevers website. On the left hand side there is a Contact button. Send her an email, tell her your problem, and ask if she can suggest where you might find additional coordinating fabric for this line. Also, go on Northcott's website, get their phone number and give them a call. I've had this same problem in the past, and actually the designer herself had EXACTLY the amount of fabric I needed to complete a quilt -- which she sold to me directly. As a very last resort, go onto a website called: fabshophop.com and do a search there. They have hundreds of shops nationwide that participate in their program, and you just might get lucky and find what you are looking for. Good luck in your continued search!
Jane