Hi Kitty,
We use the same universal boot on the icefit mens and womens suit. Therefor the sizing in the charts is kept the same. Note: it is a size 7 mens in the medium suit, and in the overall comparison spectrum, they run a little small. You should also try them on with the foot thermal protection you intend to use. Generally speaking this increases your foot size considerably.
If you still find a boot replacement is necessary, you can contact the good people at USIA drysuits. (They have a forum here on the board). They have partnered with us to do any repairs or boot replacements. If you would like to call them directly you can try 800.247.8070.
Thanks,
Zak