I feel the same way as you do. The last time I wore a dress was 15 years ago, and only because it was a fancy play. I support you 1000% and may the person with the answer to your request hurry the heck up, and post it! I will likely follow the same course as you, except I have a king with whom I am in love with, and none shall take his place.
Good Luck, Xeny
Some people never go crazy. What truly horrible lives they must live.
Now, I haven't really dealt with clothing, or CAS related items in general, but I might as well provide some information. Grim provided a tutorial (sticky in this section) and tools, with which you can clone an existing clothing item. When you create a new package with the cloned item, you can then change the flags on it directly from S3PE:
1) Mark the CASP resource in the list
2) Click on the Grid button
3) Go to Age Gender -> Gender and modify the Male and Female flag respectively
This should work in regards to having the clothing item available for the other gender. However, keep in mind that the clothing items weren't made to be worn by females, so it might look weird. It won't reflect female features and it won't have morphs for the pregnant state either.