Do you think she too young?

theres this girl who works at the same building as me. I run a non-for-profit with 2 other guys, i'm 24 and the other 2 are 27. I have been talking to her a little bit, and found out she is going to be a sophomore in college, she's 20. is that too young? one of the guys i work with gives me a hard time, it's funny though because he is 27 and just broke up with a 20 year old lol. so i don't think his 7 year difference is anything to this 4, but I don't want to feel like a creep! any advice?