I asked her about it at SDCC a few years ago and her response was more along the lines of "who can say really? That was a long time ago." Besides, didn't she not come onto the show until after the pilot?
I've spent a lot of time looking at every possible reference photo I could find, and it just doesn't look anything like that ribbon. Also, when Mal switched to jeans near the end of the show, the stripes weren't tucked into a seam at the top, they just cut them off, and the way they frayed was exactly the same as this striping, and nothing like how grosgrain behaves at a cut end.