A lot depends on what they're saying. In most areas you can sue them for slander or liable if you can prove what they said wasn't true and it cost you money like you lost your job or it damaged your reputation making it difficult to make a living.
None of us get to choose our parents. If you are unfortunate enough to have a bad one, the most important thing for you is to make sure her behavior doesn't become part of your personality. Do a good job on your school work and learn to be responsible so you'll be able to live on your own as soon as you can.