Looking for advice on a delicate situation with my ex and our kid

My daughter (12) wants to go to a concert but her mom (my ex) won't let her go. I think she should be allowed to go - it's age appropriate, safe venue, I'd take her. But I also don't want to undermine what her mom decides. Do I just stay out of it or is this something I should weigh in on? This co-parenting thing can get complicated sometimes and I'm not sure I'm handling it right.