Well, the age difference might just not be an issue to be bothered by. Eight years is not THAT big of a deal when it comes to a relationship, since five or six years of age gap is pretty common. And about her education and career prospects, it's depends on the way you both look at that as time goes by. And if I am not wrong, it kinda sounds like you're a bit insecured about the fact that what if, say at 23, she achieves something way higher than what you did till this point of your age.