When the punishment associated with a crime is more harmful than the crime itself, then there's something wrong with the law.
I don't defend the mother's criminal behavior but consider her action relative to the behavior of other parents/guardians:
Serving children alcohal served with a meal. Alcohal is a drug too. Some children might become alcohalics as a result. How about communion?
What about using drugs including tobacco and alcohal in front of children? Does that increase the chances a child will use those drugs?
Prescription medication is a whole other area of child drug abuse...
In this case, no one seems to care that the mother was motivated by good intentions. But since her actions were misguided, the legal system split up the family.
I wonder where the kid spent the time his Mom was in jail? Was she a single Mom? What did her jail/court time cost taxpayers?
Did other options exist? i.e. councilling/montoring
Drug use is a problem. But handing out jail sentences to drug addicts doesn't seem to work in most cases.
Most reformed drug addicts graduate from AA or NA which are free programs unlike prisons.