What to do if my mother is on the road to becoming an alcoholic?

You can't MAKE her: Not drink. You can express your concern, and try to communicate caring, love and wanting her to be happy and healthy, as can other family members. Unfortunately, this is often seen as 'nagging' and she may distance herself from you and others. Try attending alanon meetings, where you can learn to deal with your own anger, guilt, shame and other emotions, which may help you(not her).Family therapy.