I am Woman, watch me grade

I can't help it, my hope for humanity wanes when I read paper after paper telling me that slavery was on the decline after the Civil War or that Jamestown was a sexy place. It's not just that students can't write well, it's that they can't seem to write at all. But over the course of the last two semesters (when I've been grading for two different women's history classes) I've noticed one particularly irritating gaffe that students make: they turn "woman" into a proper noun. As in George Washington, the Grand Canyon, Paris, etc. They write things like "she was a Native American Woman" or "Puritan Women were expected to bare [yes, that's their spelling] children." Where did they learn this???