She’s probably trying on men’s boots, which is understandable seeing as the majority of boots on the market are built on a man’s last. And even if they’re sized for women, chances are they aren’t SHAPED for women. Women have narrower heels and higher arches than men, not to mention better taste in home furnishings, so one has to accommodate those features. The heels and arch, I mean.
Have her try some Montrail Sandia Peak boots ($120), a boot designed to fit a woman’s foot. It’s not a real rugged boot, but for moderate backpacking and day hiking it’s fine. Take a look as well as La Sportiva’s Women’s Storm GTX ($190), which adds a waterproof liner to a good all-around hiker. And L.L. Bean’s Leather Cresta Hiker ($165) is a book that seems exceedingly accommodating fit-wise. It comes in women’s sizes, and in narrow widths.
Of course, it could be your girlfriend simply falls at the far-left end of the bell curve, with a heel that’s narrow even for a woman. In that case, you may have to resort to several tricks to get the boot to fit. After-market insoles are one option; Superfeet insoles ($30) are available in high-volume models that soak up some extra space in the boot. You also can buy inserts that wrap around the heel聴check with a footwear store for such a thing. But my guess is that the right boot will go a long way toward solving the problem.