Am I too old?

I just turned twenty in July and I recently met a girl though some friends. The 'problem' is, she will not be 18 until the beginning of January. I suppose I am in that awkward stage where in a year no one will care when I am 21 and she will be nearly 19 but I suppose I just want to know if it's weird now. I am aware that it is her parents decision and whatever it is, I will respect it but I really enjoy this girls company and just wanted to know everyone else's thoughts. Thank you for your time.