I guess it depends on who's running it. My DD did some "Sunday Best" pageants, they could wear dresses and frills just no beads, stones, or hair pieces. Who knows? I would think if tulle is borderline, marabou would make it even more so. Does she realize some pageants actually deduct points for overdoing it at casual pageants. I guess they feel as if it's an unfair advantage over some of the girls who came prepared to be judged wearing casual wear..
Best of luck to her though. You tried.