Should I let my daughter go to a concert with her best friend's mother and her?

I took my daughter to the AP Tour to see Black Veil Brides and noticed I See Stars started a mosh pit. Now I See Stars is coming back to the same concert venue. She's been begging me to take her for the last two months, so I know she's dying to go. She mentioned it when her best friend was at our house the other day. Her friend said her mom would take both of them since they were planning on going also. I know her mom is very active in the church and a loyal Christian, but I don't know her too well. We've had conversations, so she's not a complete stranger. I'm still a little worried that my daughter's friend will get her to do something at that concert. Her friend has taken drugs and listens to bands like Blood On The Dance Floor. I'm afraid she'll get my daughter to use drugs or lose her virginity or something like that. From what I've seen, her friend doesn't seem to be bossy and do things like that, but I'm still not sure. Her friend is very sweet and polite, but she seems to be a little slutty. I'm mostly worried about the mosh pit because my daughter got pulled in and done the "wall of death". If you've never seen it, it's like tackling someone in football and is very dangerous for people the size of my daughter. I'm afraid the woman taking them might not notice and she'll get hurt, but I think my daughter could be more careful. At the other concert, she walked right through the mosh pit so she could get up front. So what do you guys think?