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.
The contact hypothesis is a theory in psychology which suggests that prejudice and conflict between groups can be reduced if members of the groups interact with each other.
Found this online hope it helps!
Encontró esta esperanza en línea que ayuda!
http://www.un.org/esa/socdev/unyin/documents/ch04.pdf
I did not write this, please dont give me credit for document.
<span>No escribí esto, por favor, no me dan crédito por el documento.</span>