Next time a present-day size 10 woman (or, god forbid, 14! 16! plus size!) walks into your store, if you could refrain from sighing dramatically and giving her a cautionary lecture about how "clothes were SO much smaller back in the day, and even ten years ago women did not look like, well, that, and maybe you'd better just leave because we don't serve your kind here*," that would be great. I think a lot of self-worth could be preserved. And you might even sell her something.
*So I may be exaggerating a little, but seriously, just a little.