ranking mutual selection

I have a sorority for dummies question. My sister is rushing at SDSU. She has to rank the houses after the first round. She visits all nine and ranks. She can go back to six the next round. Let's say she is lucky enough to get her top six listed. What happens if she then dropped by them through rush. Is she out or can the other ones come back somehow, The ones she ranked lower earlier in the week. Yeah I know she probably wasn't paying attention or asking questions but it was pretty intimidating. Thanks for being nice