Yes, it's pretty competitive. Without recs or knowing the "right" people, you're choices will probably be narrowed down to 5 of the 9 sororities. And most sororities avoid taking sophomores unless they just come with THAT good of an application, but most sororities if not all will take one or two sophomores. My best advice... go through recruitment open-minded. Don't decide before you go through where you want to go... because otherwise you may be disappointed or you may go through and realize that reputations aren't always true. But, yes, definitely tell her to rush, and tell her to avoid listening to the talk outside the rooms about the sororities and make the decision on her own.
PS-Make sure she's aware of the range of dues. This year they go from $1,000-$3,500/year. She needs to be aware of the cost of living in a house/cost of not living in a house, etc...