Well if she really is in Wyoming, it probably gets pronounced every which way but correct. I've always pronounced it prew, but that's because I've had some French. In Wyoming, they do change things a bit. If you go to the town of Dubois and pronounce it "Doo bwa" they will know you are a "furriner" because a native will say "due-boyz." There are a few others, too, including Belle Forsche (S. Dak) which is commonly called "bel for shay" instead of bel foosh. So, wherever she may be, in Wyoming, I'll bet one or two have called her Mz. Prewl or Prewlex.:-)