The song is about an over the hill groupie that followed them around constantly. She would show up drunk, and interrupt the bands recording sessions. Jimmy page got even though..... He walked into the booth, picked out a homely girl that was there, and demanded that the old tart give up her seat so that the girl could sit down. The older woman sat there for a few seconds stone faced, and then got up and left, never bothering Led Zeppelin ever again.