I think I would have told her where she could stuff her fabric and then turned around and left.
Like others said...if she wanted it then why did she have it out for you to look at. This sorting and keeping should have been done previously.
Did she have this advertised for sale or did someone tell you that this lady had fabric she wanted to get rid of and you both set up a time to meet at her house? Seriously...first thing I would have said to her was...are you selling this fabric or not? And if she said yes then I would have said...call me and maybe I will come back after you go through it because it looks as if you put an ad out without knowing what you were doing. And me standing here while you pull stuff that I want to pay for is a waste of my time.