Check out Frey Daytona Lady Star GTX
Frey Daytona makes great waterproof boots (a little pricey, but worth it in my opinion). They have flat, oil and slip-resistent soles (no heels to catch on footpegs). They have many different models for both men and women. The Lady Star GTX model I use actually has an internal lift (I'm only 5'2), allows me to touch the ground more comfortably. The one feature you'll like is that it's ADJUSTABLE in the calf area - whether you have shapely/athletic calves, or just an extra layer of jeans or heavy socks. You can instantly make them an inch or so bigger just where you need it.
They're only imported to the U.S. by one company that I'm aware of - Helimot ([url]www.helimot.com[/url]). My oldest pair (daily riders) is about 10 years old now, and just last year started leaking in heavy rain. Prior to that I'd actually stood in standing water after a heavy rain, and the only reason one foot got wet is that the water sloshed over the top of the boot. My hubby bought me another pair about 5 years ago, which I reserve for longer trips. Santa brought me another pair last Christmas. :-) The newest set came with zipper pulls (which in my opinion was the only thing lacking in the older versions of this model).
I recently spoke with another BMW woman rider at the AMA Women's International Rally in Carson City, NV, who told me she'd returned hers for refurbishing. For much less than the cost of a new pair, her old ones came back looking like new. So I'm thinking about checking into that for the oldest pair.
Good luck with your search!