@alvertonch I remember my girlfriend from that age. It's amazing how much you grow from then, just know that you want to be the positive influence on her rather than the demanding dad. You may try to stop things from happening that you don't approve of, but you'll fail. A guiding parent will have much more influence than a demanding one.
There is high likelihood that this is the first relationship of many in her life, but there is that strange chance it won't be. Help her grow as a person, you never know if that boy could grow into the man that becomes the father to your grandchildren.
I say all this remembering my girlfriend from highschool, started dating at the same age as your daughter. 19 years later, she is in the other room with my boys 3 and 6 now. You never know how life will go.
@alvertonch I saw that post and thought that people were quite harsh with you. As a dad of both a 14 year old boy and girl, I do think 14 is a little young to exclusively date. There is a lot of maturing that takes place between 14 and 15, and 15 and 16. Be sure to talk about boundaries and what a healthy, normal relationship at this age should look like.