If her high level of training made her miss out on a period the last couple of months only to get it when she tapered before the race, well, I have some sympathy for her. It may be a sign that she's well rested and perhaps this makes it somewhat common (besides normal cycle) for women to get it right before big races. I would be curious to have a study done in relation to period suppression in elite endurance athletes and if tapering has higher than normal odds of bringing one on.
Anyway, still a decent run by all the ladies up front.