Maybe this would be a case for positive reinforcment. It's easy to act bad when everyone else is doing it. But the truth is kids naturally want to please their parents. If you reinforce the good behavior, like if no bad words are said, give special time like reading a book together, or a trip to the park, something simple the child enjoys, something to look forward too. And explain at the time bad words are said, that it hurts your feelings and do not approve and have her apologize, then hug and tell her thank you for understanding how this makes you feel and tell her you love her. And drop it. Then start over with the no bad words. But remember kids don't have the attention span adults do... So in order for this to work you have to have patience and be on top of it all the time. I would also speak to the person who says this kind of trash in front of her. Let them know under no certain terms will it be tolerated anymore. This is a form of abuse! Medication only works if the enviroment changes. Positive reinforcment is an enviromental change, be ready though this does not happen over night.