agree !

I would go back and explain what happened.

Honestly, I just don't know what I would do!

I'd go back on a day when she was there, explain and ask her what you should do. If she wants you as a happy returning customer, she'll make it right. Word of mouth is an amazing thing.

If she doesn't make it right, then purchase (ELSEWHERE) the material you need to give the back a border. I've seen backs before that had a strip of pieced materials from the front that looked neat. I'll see if I can link that.

http://www.quiltingboard.com/t-150277-1.htm#4121560

That is what I would do. In our shop if that would happen, I would hope you would call and bring it back in. I would re cut it to the right length at no additional cost to you and give you a coupon for 15% off your next item.

I guess I would do my own measuring, if it is wrong I am responsible for the mistake. I always plan on some extra.

Everyone makes mistakes. She was trying to help you save on fabric. I would go back and just joke with her about the mistake and buy the extra. If she had measured correctly the first time you would have had to buy more anyway. Piecing the backing is no big deal.

If you don't want to go back you could always split the backing down the middle and add a strip of a blending fabric. I have seen people do this and it gives the back a little pizzaz.

Also, can you tell how much the fabric shrunk when you washed it?

I would go back and talk directly to her but start the conversation with"remember when I came in the other day and you helped me with the calculations for borders and backing using your calculator and you told me this is the amount I needed". Because once she says she remembers she's committed.

Yes, go back to the shop owner.