I reckon there are 2 reasons women aren't much into this hobby. Firstly as someone else pointed out, typically women aren't big on playing with "toys" = finicky equipment. Secondly, astronomy as a hobby is usually quite solitary - and women prefer more communal activities. Just have a look at a star party's gender balance - you'll usually always see more women because of the social interaction (and hubbies with telescopes). Most are probably truely interested in astronomy, but not as a hobby. Men don't care - sure it's nice to hang out with others sometimes, but all we need is a dark sky and a scope.
Hey Jen, I'm no chick (sorry!!), but I'm free any time you want some astro-company!

The drive might be a bit of a bugger though.

BTW, my wife will be the one inside making the coffee and chatting with your hubby.
Cheers, Marcus