My question involves child abuse or neglect in the State of: CA

I know a family in which the mother smokes pot in front of her children sometimes. In California, is this legal? Is it child endangerment, or just dumb?

I also happen to know that this same mother is breastfeeding an infant, and may or may not be doing other illegal drugs (cannot prove, though).

If this was reported and investigated, how likely is it that CPS would order drug tests on the children to test their exposure?