Is it permissible to abandon a female friend who deliberately causes harm and offense without provocation?

Boycotting is permissible to avert religious or worldly harm, not for worldly gains. For often, a graceful boycott is better than a harmful association. Your friend is abusive with her belittling and hurtful actions, as mocking and despising others are forbidden in Islamic law. This friend should be advised kindly. If she does not desist, then boycotting her is permissible. However, boycotting should only be resorted to if a benefit is expected from it; otherwise, reconciliation is more appropriate.