The female customers are "underserved" because (and I firmly believe this) they do not care as much as men about watching their programs in HD. It isn't as important to them as it is for men. Many of the women I know don't watch the HD versions of the channels they do get. I have told my mother-in-law many times that she gets A&E HD and TNT HD, yet she is constantly tuned to the SD version of the channels and is happy with the pq. I have seen many examples like these with females. They just aren't aware as much or appreciate HD the way men do. How often do you see a woman alone at the electronics store drooling over the HD televisions? But watch out when they open a new Saks, Macy's, Talbots or whatever.
I am not much of a sports fan (except for hockey and a little football) but we can thank sports fans (mainly men) for the growth in sales of HD TVs as much as we have seen. First came sports in HD (and the late night talk shows), network programming, and then many channels aimed at men, including some of the most popular cable channels. It is only logical that they would go HD with any popular cable channel, eventually. Lifetime is very popular, but I honestly don't think women care as much (in general) about HD and that is why this popular channel's HD version hasn't been carried by too many providers or demanded much yet.
I think them adding Lifetime and Lifetime Movie Network in HD is more about being one of the few providers that actually do carry them. That is a selling point. And sure, there are some women that care and they will catch a few new subscribers.