Need some help here...

So, my husband's family is really mean. Back in the days we dated, his mom was hateful toward me one minute and then nice to me the next. We got married in 2014, had a baby last year. His mom is really bitter and she hates everyone, especially me. I've always been nice to her for my husband's sake. She came by in February to see our daughter on a visit and she kissed her and left lipstick on my baby's cheek. I thought she scratched herself again and seemed concerned for a moment until I realized what it was. I thought the visit went lovely but she called my husband a few days later and said that I accused her of hurting my daughter, which is stupid and I would never do that. She stopped calling. Didn't even call my husband on his birthday. His sister only heard from their mom what happened and sent me a text that basically cussed me out and she wouldn't talk to me either. Now they want to start coming back around to see the baby and I don't feel comfortable with that sort of behavior around our little girl. I want her to know her family but I don't want them to be source of negativity and constant disappointment and distrust to our daughter as she grows up. What should I do?