Make it a sisterhood event with the non-players coming along and cheering for you guys.
We never did practices for our intramurals though, and our team was pretty "hard core." Well, you know, IM hardcore
Play co-ed sports? Then you need fewer girls, but playing with guys is fun.
Don't try to force yourselves into sports you're not good at. Play one or two that people WANT to play, but don't sign up if you're not going to do it.
If people do sign up, fines if they miss a game? Your chapter is paying for the intramural fee (ours did) and it's wasted if you don't play. It's rather extreme though.