what do sororities here look for in pnms?

Assuming you pass the GPA cut off ... sororities value looks and personality. Which one is more important depends on the sorority ...

Here's some info about rush for you first years unfamiliar:
There are I believe 4 rounds of rush. The first round, you go to every house and then rank them 1-15, and each house ranks you as well. You can get invited back to something like 8 houses next round. But some girls get invited back to less depending on how many sororities liked them. A computer magically does all this sorting via some mysterious algorithm. Each round, you rerank the houses and the houses rerank the rushees until the last round - prefs, where a rushee can visit up to 3 houses. So, my little sister's hallmate rushed and she is rich, went to a private VA school, "isn't great to look at" (my sister's words, not mine), and has a meh personality. She ended up with 2 houses for prefs: KKG and SSS because she didn't get invited back to any other places. She obviously knew people at KKG and SSS probably only invited her back because they need help filling their classes. If that is what makes KKG "top tier" and SSS "bottom tier", so be it. My point is, rush is a crap shoot so don't worry about it. It's an imperfect process but it gets the job done, that is the job of building smaller communities of belonging within the larger UVA community.

Basically being able to hold a conversation for 20 minutes that isn't awkward is the first threshold, but then you have to stand out to the members you mesh with. A lot of girls don't understand why houses drop them because both they and the members they talked to had a pleasant time. But for the houses everyone wants, you must get above-average scores/comments EVERY round to keep moving on (since most PNMs want these sororitys, they don't have to ask as many girls back). An "average" review by a sister doesn't get you anywhere with the more popular houses. Making sisters remember you and being sure they have more to say about you than "she was nice and cute" is huge