Slander is communication of false statements injurious to a person's reputation. You can sue if you have been defamed.
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Good luck to you.
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While it is true that defamation can be grounds for suit, you should be aware of the practical challenges. First, if she is slandering you (in other words making false statements orally), you will need to have a clear set of witnesses in mind that can/will testify accordingly. It would be far easier to prove if she was libellig you (in other words, making false comments about you in wiriting to third parties). Also, you should understand that truth is a defense, so the exact nature of her comments in context of your actions would need to be reviewed. In any event, as a practical matter you should consult with an attorney as to the possibility of sending a demand letter requesting cessation of the statements and a correction to the parties to whom she made such comments. However, given your statement that she is a drug user, that letter may have limited effect.
I hope this helps.
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