How to approach asking my mom to go to a concert?

I live in Connecticut. I went to the Webster Underground in October for an All Time Low concert. And, I'm going back in February for We The Kings. I'm fourteen and my friend is thirteen. My mom didn't mind me going alone. Trust me, the venue is REALLY tiny. Take it from me, you will be fine. There are security guards all over the place and they make sure it doesn't get too crazy. Just tell her that you will be super careful and you will call her as soon as the concert ends.