Personally I believe it is a bad idea. For those who say, but it's not illegal in my state/area; I say - just because something isn't illegal, that doesn't make it right. What if an emergency with her kids happens when mom is high? Sure she can call 9-1-1, but if her high hinders her from giving assistance to her kids and something bad results, she should be in a heap of trouble. (I say should but unfortunately that is not always the way it works out)...
Different drug, but a few years ago in late December in this area a mom who had been drinking and taking cocaine got into a fight with her boyfriend. She decided to leave but first had a friend who had also been drinking come over. This was at her parents' house who lived very close to a riverbank. Mom puts her two kids into her friend's car because she had a car seat. After the kids were strapped in, mom for whatever reason decides that she is going to drive herself separately in her own car. Drunk friend then backs out of the driveway, across the dirt road, and over the retaining wall into the river.
Long story short, drunk friend is able to get out of the car, seven year old daughter is able to be rescued; four year old son strapped into a car seat drowns.
Drunk friend is now in prison for a very long time. Somehow, mom is not (and blames drunk friend for her son's death). But it was her stupida$$ decision to put her own kids into the care of a drunk driver. Had she not been impaired herself, she might have had a clue that the friend was in no condition to drive either. The two kids were 100% innocent victims in all of this and did not deserve to be children of this selfish idiotic imbecile.
Some would say that my story doesn't apply to the topic at hand because this mom was high on cocaine rather than marijuana. So in anticipation of that I ask if there is really a difference. Impaired is impaired regardless of the severity or source.