Just a quickie to thank everyone for weighing in here with suggestions for my DD's BF (jean) problem.
We have found a temporary solution. At the B&M GAP we found the very last pair of sexy BFs available in any size and snatched them up. We also got her one pair of sized up straight jeans as per Greyscale and others' suggestion. She was a little less happy with the cut of those but liked the fabrication and light wash on this particular pair, so we'll see.
I also got her two pair of the Old Navy BF straights that Carter recommended. Again, she is not 100% convinced on these, but she did go out the door in them this morning, which is a hopeful sign.
Thank you all for your help -- I knew you'd have her covered in no time!
ETA: the 501 search is ongoing. New version nowhere to be found here in my city yet; older versions not available at thrift in her size last weekend.