Use regular reminders of personal motivations like family, career, and health.
Or
Keep his schedule and friends as consistent as possible to avoid too many changes
I was once a drug addict, and both of these things helped. Keeping a tight schedule and sticking to it really helps, especially in the beginning. And Using regular reminders of what you will lose/ and what you want for your future are both ways that really helped me.
The best way would be to explain to them that she does not drink. If they do not respect her decision, then simply that is not the group of people she should be around.
