Hi there, thanks for asking. If you think the reason for low potassium is drinking, she should have low magnesium
level as well. Many medications could lead to low potassium as well. Lithium
can cause it and it is used for bipolarity. Many anti hypertensive medications can cause low potassium level. If you and her doctor cannot trust on her not to drink alcohol, she may take a medication like disulfiram
to avoid drinking. She also can join AA group therapy sessions in order to pass successfully the different stages of abstinence. I wish a good health for her and the family.