Just to chime in (haven't been on gc in a while

), as a mom of sons at UT, Round Up is a BLAST!
Looking at their pictures, it is clear that it is as much or more of a sorority recruiting event as fraternity. Not only are all the sorority girls wearing startlingly bright clothes and accessories with their letters proudly displayed, but the boys are wearing them as well. At chapter on Monday before Round Up, the sororities come by and drop off their gear at the fraternities, and the guys line up and take what will become a staple for their upcoming year's wardrobe (thank you, girls

!).
Anyway, many, many high school girls attend, going in groups and staying on floors of sorority girls hosting them. These are pre-pre recruitment unofficial visits, and do not fall under the silence period. Panhellenic recommends that seniors not attend, but they do (just as they did back in my high school days - the more things change, the more they stay the same at UT).
As long as girls are in a group, have no preclivity for wild behavior (and want to have a successful rush) especially if they are staying with upperclassmen, they'll be fine - they'll be escorted from party to party and watched over like little ducklings.
And -to answer before it gets asked -
Camp: as in Waldemar, Mystic and Longhorn (co-ed) -popular girl's camps in Texas where a ton of future Longhorn Greeks go every summer since they could walk
NCL: as in National Charity League - a volunteer organization that moms and daughters participate together in requiring a certain number of hours at designated charity organizations, starts in junior high, goes through senior year, culminates in a fancy "Presentation" event.
As a boy mom, I'm glad to say I didn't have to worry about this stuff!