In the strange royal close-friends circle Chelsy may be the best/normal person Harry will ever come across. If he and his brother William had moved/and went to a foreign college they would have had a better chance of meeting others not in their close-knit circle, but that didn't happen. Almost all the other Royals were sent away to school to "further" their social education.
Lynda, I agree with you. I also think that Chelsey is very normal and perhaps, given Harry's options, she is the best normal person Harry will come across. Sandhurst did not provide many options for dating/marital partners.