This site explores the original card file method introduced by Pam Young and Peggy Jones' book, Sidetracked Home Executives(TM): From Pigpen to Paradise, originally published in 1977.
Since that date, the "SHE classic" card file system has been used successfully by thousands of S.H.E.s.--and although Flylady's system is different, it is still built upon the same basic principles taught in this book.
With all due respect to Marla Cilley, there is no "one right way" to get organized. If Flylady's version of S.H.E. works for you, great! But for many of us, "SHE classic" is still the way to go, cardfiles and all.