Recs weren't required at my school or for my sorority. I don't think we would have known what to do with a rec if we'd gotten one
I always thought that any mention of recs on the application form, website, information pamphlet, etc. (e.g. "Oh, don't worry about recs, the sororities will get them for you") was secret code for "You'd better have a rec if you want to get past round 1." Unfortunately, many PNMs don't figure that out until it's too late!
It's still best, I think, to line up recs on your own. Who's going to write a better rec - your mom's best friend who's known you since you were born, or some stranger you've never met?