You could tell her she is so nice to offer to "help" you and she can have whatever she wants - its only $15 a FOOT, cash only, NO credit even till payday. If she wants, you could offer to save it till she can come back with cash in hand then she can carry what she pays for. It would save on packing, moving, and unpacking plus you could get more at those prices. Lots more but I have a feeling at those prices she won't nibble.
OR
You could just say no thank you this material is the first thing I want off and in my new sewing room so I have something to help me relax after long days of unpacking.