While I have no issues with Women in the Military there are many IRL issues with women in frontline combat. I can say that some of them are already being brought up. The following Essay is a pretty good summary of the issues.
Amazon's Right Breast By Tom Kratman
In my games and In my writing I do have women who get into the thick of combat. Now most of them are not ordinary women. Most of them are Augmented in some manner. That being said there are reasons to attach women to frontline units. In the Fluff of TW2K it seems that various Militaries just needed any body that they could get. Thus you end up with women on the front line.