I'm almost positive that the one-year rule refers to the day you sign your bid card, not the day you depledge. I've seen women go through fall rush, pledge, depledge, then rush again the next fall.
This rule applies to colonies too - if you join a colony and then depledge, you have to wait a year from the day you pledged.
DeltaZeta2003, if it's been a year (sounds like it has), your friend should be ok.
