My Friend IV Used Meth,and Herione.shes 38weeks Pregnant,she Wnet To

My friend IV used meth,and herione.shes 38weeks pregnant,she wnet to dr today amd they wanted to take her to emergency c section due to babys position being breached, weight on low side,and low fliud. Shes needing to know how long its going to take to pass drug screen at hospital,labor&delievery? And what all can she do to clean system asap,as well as keep baby healthy as possible???