I don't know what room these are going in and if you would like this look, but perhaps you could add a band of 10" or 6" brown fabric along the bottom? I've seen that blocking/banding done and at least you could salvage the drapes that way.

What would you think about a 10" wide border on the bottom? I've seen that done in many model homes and always love it. If you have a machine it would be easy enough to do. If not, I understand (and appreciate since I'm often the seamstress for friends!) your reluctance to go back to the friend's mom. But I think if you just tell her, "Ohmygosh, somehow I mismeasured!" and then share your idea for adding the bottom border she probably wouldn't mind terribly. Especially if it is accompanied by a gc to her favorite restaurant. You could even offer to undo the existing hem, since in my opinion, that is the worst part of the job. The fabric you chose would pair well with a tan/cocoa minicheck, all kinds of things...

I love that fabric; it's so rich and warm looking.

Letting the hem out is probably going to give you about 3.75 inches more, because you still have to have a small hem. Using clip rings would give you a little more length; just how much depends on the size of the rings.

So you are pretty much left with adding some sort of border to either the top or bottom of the curtains (the bottom would be easier) or moving the rod down, or some combination of the two.

The only other thing I can think of is if the header is fairly deep you could let some out of that, but you would lose the pinch pleats and the lining might not be long enough.

Or hang them the way they are and move the sofa in front of the window so no one can see the bottom of the curtains.

When I got my master bedroom curtains custom made, I had a foot long border of a contrasting fabric added as a design feature. The same contrasting fabric was added as the panel for the grommets, and as 1/3rd of the outer side of each curtain.

Not sure if it helps you, but I just took some pictures for you to see what I mean:

Could you hang the drapes on rings? Between doing that and letting the hem out 3 inches, you might only have to lower the rod a couple of inches.

What if you added more of the same fabric to the bottom and did some kind of welt or trim detail to cover the seam.

I think with that design of fabric, palimpsest has the best idea.

Those are all awesome ideas!! I'm definitely keeping them in mind for my next house (which I'm hoping is sooner than later).Anyway, in my moment of panic (how silly is that?) I lowered the rod, put them on clips and hung. They actually look really beautiful. My friend and I figured that her mom forgot the length and just made a standard size. I also like the puddle effect, but these just skim the floor and they look really nice too. They are on my two living room windows and the fireplace is centered on the wall. The fabric is very lovely and has warmed my room considerably. Much better than the earthy green dupioni panels I made myself. OH, and the fabric was only $3.99/yard!! Thanks to Fabric World in Stone Mountain, GA (hope I can say that here). Oh well, I feel silly for over reacting especially as I'm peeking over my shoulder into the living room. When I get my camera working I'll have to post pics of these and the set that she made for my hideous south facing, full sun palladium window in my bedroom.

So happy that it all worked out...can't wait to see pix!