I don't know if these would work with such a big group, but I remember the sisterhood sleepover my sorority had right after I was initiated. It was a ton of fun. We devided into two teams and did an "Iron Chef" competition for dinner. One team was Italian and made pasta and salad w/Italian dressing. The other team was Chinese and made fried rice. Then we had a pseudo-scavenger hunt. But instead of going places to find stuff, you'd look in the stuff you brought. The items were stuff like facewash, deoderant, pajama pants, nailpolish, eyeliner, etc. We were in teams and whoever got the item out of their bag and to the front of the room fastest, won points for their team. And at the end of the game, everyone got a prize (chocolate
). And then afterwards, we gave each other makeovers and did each others' hair and took before and after pictures.