Time in the water and a little conditioning will probably solve the consumption disparity, unless you are cold and then a warmer suit would be a better investment...
My point is only that it is not all about conditioning, some folks just use more air.
Emphasis on the word probably. Experience is usually the biggest factor with new divers and air consumption. Aquaregia's will likely get better unless his number of dives estimate is out of date.
Female air consumption is a different matter entirely. Many females can easily exceed no decompression times on a single 80 Ft³ cylinder. In addition, they usually have a harder time maintaining core temperature in Northern California. Maybe the answer is to get a smaller bottle for her?