First, at 14 you should not be sexually active. Youa re not done growing so you cannot expect it to be large yet.

i dont think you should be haveing sex or even worrying about sex
if she doesnt understand that then why even be with her?

another thing if you have sex she could get pregnant or you could get an std
would you want either of those things to happen?

There is nothing you can do except wait 'til you grow a bit more.

If you really like her as understood as a mature individual, you wouldn't have sex with her by the third day of the relationship. It's suppose to be among the ultimatum of the relationship, not the first activities. I am going to assume she is 14 too, I don't think (hope rather) that she is particularly experienced at that age. If you guys are going to have sex, I don't think she'd have this vast knowledge of preferences to be like "ugh a 4.5 incher? pssh". Then again, I don't know how 14 year old girls think anyway, thats why I'm not that close with my sister I guess -_-. Remember to use protection if you must do this kid.