I am looking to do some mountaineering with my wife this winter and we are having a hard time finding her good cold weather boots that will both keep her feet warm and be comfortable enough to hike in.

My wife is small, size 4 womans or childrens 2 1/2.

We will be in temps from -30 deg below, to 40 deg. I was hoping for something versatile between a pacboot and cold weather hiker. I would love to find quality footgear for her, I have an excellent range of boots from pac boots to cold weather hiking for myself but cannot find anything of good quality in her size.

brand recommendations anyone?