Is 18 and 16 weird?

For context, me and my girlfriend have been dating for about a month now. I’m currently 17 and she is turning 16 in May. I have a late birthday so I am only one year difference school wise. I turn 18 in October and was wondering if this is a problem or weird at all. We have the same humor, watch the same shows, and really enjoy each other’s company. I just need some sort of insight or something because I don’t know if it’s wrong or not. We really like each other but sometimes I think it bothers her.