I know women who have said kaddish for their parents. They said it out loud, the same way a man would.
When I turned 12, my uncle asked if I wanted to take over saying kaddish on my fathers yartzeit. I tried it once, but it wasnt really for me. I agree with oomis about worrying about the things I have to first. I told this to my friend who wears tefillin (as to why I dont 😉 and she went on a rampage 🙂