my daughter dating?

My 13 year old daughter is dating someone on her shooting team. He is 16. (Turned 16 this year and my daughter will turn 14 in september). I'm trying to tell her that you don't date team mates or people you "work" with but she won't listen. What would you do as a parent? Knowing that your 13 year old daughter is dating someone 2.5 years older than her and they are on the same shooting team.
I'm dissapointed in her, he is way to dorky for her and not her type. He's smart in all ap (college) classes and she's barely in advanced. I don't get it
Edit - she won't have sex with him so what rumors would be spread? She's not that type of person I KNOW that for a face