My husband doesn't stand up to his mom

My mother in law is so awful and I hate being around her. She has never said anything nice about me or anyone. She tried to talk my husband out of marrying me at our wedding and she loves to bad mouth me to everyone. She got mad because I didn't let her pay for my wedding dress. She said I'm trying to push her out when in reality, I don't want her to hold that over me because she will. My husband doesn't stand up to her at all. He's not a mamas boy or anything. They actually aren't close at all, but growing up his siblings knew you shut it up, moms always right. If you speak there will be serious consequences. He never told me what those consequences were. He doesn't like to talk about it. And when I asked his siblings they won't say either. They just say "It was serious consequences and I rather not ever think about it." So I really don't know anything about his childhood because he refuses to talk about it. He was just taught he better shut up when it comes to mom. We honestly try to avoid his mom but she lives so close. My husband will usual ignore her calls but if he does that she will show up at our house. She loves to make everyone around her miserable and me especially. I just wish for once he could put her in her place, but nobody does. Their dad doesn't even argue with her. He just shuts up. I'm so sick of her.