Divorce the answer?

Is there a way to get divorced without spending loads of money? My stepmom is psychotic and my dad knows it. But we're not rich, we can't afford a divorce. She's killing him. We own our house and she works at Food Lion. Big deal. I hate her so much. Hate is a mean word, but it sure describes her. My counselor even agrees with me, thinking she is schizophrenic or bipolar. And suggestions would really help!