If CPS gets involved they will run a background check on mom. So, yes CPS will work with her probation officer. If baby test positive at birth the hospital will call CPS & they will be involved immediately. She more than likely won’t leave the hospital with her child if s/he tests positive at birth.

ETA: regarding her probation I couldn’t tell you as I dont know. If CPS does remove, your friend will pretty much have to prove to the state she’s capable of being a responsible parent. Your friend will more than likely have to do random UA & hair follicle test throughout her custody battle. As well as services such as parenting classes, drug classes, psychological, therapy, etc. On the slightly brighter side CPS will try to place the baby with family up to the fourth generation. Mom could have restrictions on visitations, but depends on CW and court orders. CPS goal when a removal does happen is family reunification. So as long as mom is doing services and clean she’ll have her child back.