Is it permissible to boycott a sister who openly smokes cigarettes and does not wear the hijab, knowing that she does not respond to repeated advice?

Displaying oneself immodestly (tabarruj) and smoking are both forbidden. It is obligatory to advise the sister who commits these acts with wisdom and through diverse methods of da'wah (invitation to Islam), such as explaining the religious ruling, offering admonition, providing tapes and booklets, and involving the husband in the advice, reminding him of his responsibility towards himself and his wife, as Allah Almighty says: "O you who have believed, protect yourselves and your families from a Fire." If the advice is not effective, it can be repeated, or she may be shunned if shunning will deter her. Otherwise, reconciliation is more beneficial than shunning. Effort should be made in advising, and shunning should not be resorted to except when despairing of the advice being accepted, and provided that shunning would be beneficial.