Originally Posted by
Tim_Iowa
It doesn't, directly.
But it's tough to design a bike with a short enough top tube for a small woman if the bike is designed around 29er (622 with 2" tires) wheels. By no means impossible, but the geometry gets wacky. So, a bike designed around smaller wheels can have more ideal geometry AND a shorter top tube.
Is your bike the smallest size in that model? Sometimes a smaller size is available but not in stock at the shop. Not that it would help you, but just saying that "29er wheels" and "fitting you" may not be exclusive, with the correct frame size.
For your bike, see if you can borrow some 27.5 wheels to swap in for a test ride?
My baby is
this, a 2016 Liv Rove Disc Lite, in size small. It does come in XS, but I thought that would be
too small. I wanted a rugged, do-everything bike and I didn't have a ton of money. The Giant won out over the Specialized Vita by a nose. I've learned a lot in the last two years, and I still think I'd go with the Giant. Probably.