Some of my suggestions have been said already, but that's okay
1) Definatley redo the website. Which you said you are looking into. It needs a face lift and an update. I would suggest getting rid of the HOT pun (which you have already agreed that it probably shouldn't be there). I also noticed that your national site and the Gamma site were very nicely designed. Both including more facts about the founding of Eta Omega Tau and the national site also listed facts about the sorority (colors, flower, motto, etc...). You will want to sell yourselves through the website.
2) Now I don't know much about locals (being in a national myself) but do you have a main philanthropy? If there is a main philanthropy that y'all devote a majority of the time to, list it. Talk about it. Some women are not only looking for the sisterhood experiences but they are also looking for the volunteer and philanthropic activities. All the websites kind of seemed non-committial to philanthropies. Like I said, not knowing about locals, I'm not sure if your national has adopted one for y'all. I'm not sure if locals do that in general. If they do, I would think adopting one (or two) might help.
3) Do a philanthropic activity on campus. The great thing is you are raising money for a specific cause but you will also get your name and letters out there. You could chose a fraternity that could work with you on raising money. If you have a mall (or in front of your student union) set up a table specifically about the philanthropy and how you are raising money and then set up another table about the chapter. If people stop for one they might stop for the second, especially if it is a cause that they are incredibly interested in.
Do you have alums in the area? Maybe they could help y'all out at some rush events.
Being a local do you have to participate in FR?