You have good plans already for keeping her cool but start now in getting her ready. If she is never "in the heat" it will be harder for her to adjust comfortably.
Keep a talcum powder with corn starch handy to help absorb the sweat. It will help keep prickly heat at bay (diaper area, under neck and armpits) Let her go without a diaper when you can. They are designed to keep wetness in so let her "air out" often!
Have fun and enjoy!