Look for a boot that has a wider calf opening. Us, women, get the short end of the stick - we have wider calves, which makes it harder for us to find a comfy boot.

I've been lucky with Nordicas but I also know alot of women adore Technicas. They tend to have a wider opening for the calf. I, personally, ski and teach on Nordica Olympia SpeedMachine 12. I ski every weekday, and these boots are great for doing anything, from the hardest trail I can find, to standing around and teaching kids all day long. Alot of the female instructors also favor the technica boots, since they are pretty good for comfort, yet strong enough for anything on the mountain.

My boots also have a moldable liner, which is heated by the heat from my foot (or from a hairdryer or something similar) and it molds to fit my foot, so its the most comfy for me, which is great for women's differing feet. It doesnt pinch, and the buckles are adjustable - if the default position is too big, I can move the screw down a hole and make it so they fit better. The only downside is that the velcro band at the top is not as elastic as I'd like it to be, but thats nothing big.

I hope that helps.