Should i let my daughter go with her friends to skating ring in these circumenstances?

Well first of all i don't know the girl's mother very well i only met her once. And second of all the mom is going to take them but this is what concerns me. She's going to be checking on them from time to time to run errands. And she asked the manager at the skating ring to keep an eye on them from time to time. My daughter is twelve and her friend is twelve. I am very overprotective with my daughter in this day and age. Especially with abductions and pediphiles. Thinks that's how you spell it. What should i do my daughter wanted me to ask this question because they are inviting her for tommorow.