I'm a dad with prim custody under temp orders, in mediation, but my ex-wife has demonstrated neglect, must I report her to CPS?

Kids are 10,8,6, I pay her $4,500 in maint since our sep in July 2008. We have spent $70K thus far to accomplish temp orders stating that she must go through Drug Assessment, which she completed with recom for treatment in Oct but has not begun. We are currently working with a mediator, and have a draft parenting plan-60/40 joint legal and physical custody with me being primary but she stalls and stalls. I want the kids to have the nurturing but I fear she is not all there. Today my son told me that last night she left her apartment to take her boyfriend home at 12:00 and didn't return for 30 minutes. He was crying and scared, he tried calling 911 but phone was broken. He stood outside in his pjs. This is the second time in 2 weeks they've reported being left alone while she ran to the gas station.