I'm not sure if that constitutes her as being a minor, however you are still her parent. Tell your W that you are concerned about your D and are going to take care of her. That you don't care about where she's going and that the children's welfare comes first. If she gives you a hard time about it, tell her that you will charge her with child endangerment if she leaves them unattended and can discuss it with your L but you will be taking care of your child.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.