Can someone be removed from a deed if a will is changed?

My grandmother signed her house over to her three daughters several years ago, then about three years, major problems arose with one of the daughters and my grandmother had her will rewritten and took her out of the will completely. They have had no contact since. She specifically stated in the will that the house and all property would go to the other two daughters. My mom, one of the two in the will, has been the sole caregiver of her mother for the last few years and when her mother passed away two weeks ago, the attorney informed her that the third sister was still on the deed to the house. He says that someone cannot be taken off a deed even when a will is changed having them removed. This is causing a lot of problems now. I hope this makes sense and I hope someone can explain if this true or not.