Approximately 0.135% of the population lies above three standard deviations. Not impossible, but very rare. With a large enough population, you would expect to see a few individuals with those characteristics, but they would be regarded as exceptional among the species. If that is something you want (and Sep is fine with), then I'll not say anything. 

It is far from the worst I've seen. I know of one character in a different RP whose height falls above 5 standard deviations.