this is what I was going to suggest...it won't stay flat..really...

Sorry this happened, and I hope it will fluff back up for you! Either way, she is sure to love it!

Well, so far nothing is happening. I'm just going to let it sit until tomorrow. Maybe a quilt genie will drop in and fix it. I'll let you know what happens.

if it doesn't fluff back up do you think you could find a really thick yarn or even the cotton cording for doing upholstery to stick there before you stitch the binding down?

can you show us a picture, maybe a picture will help folks suggest other fixes

Yeah, I had a flat binding due to my err once. It puffed up after washing. Good luck and even if flat MIL will be sew pleased with the quilt and the love that went into the making.

I'm hoping the quilt genie comes tonight! but if she doesn't can you just iron the rest of the border to match? Not what you were hoping for but she will think you planned it that way?

You can do a burn test on a scrap of batting, that should tell you whether it's cotton or poly. However, if it's poly, I don't know what to tell you. If it's cotton you should be fine.

Ive done that,once its used and loved no one cares. But i know how upset you are, been there. It really will be ok. Life happens. :)

have you washed and dried the quilt yet? once it is washed and dried i bet it is nice and fluffy again....we press it to make it flat...that's the point of the pressing- we wash & dry to fluff.