My Mother believes people have stabbed her and are trying to kill her in the assisted living. Any advice?

She will not eat their meals, stays in her room. She recently moved there. My father is in the memory care center, she can visit him whenever she wants. She is legally blind. She is terrified and paranoid. Relates this long story of how one of the ladies stabbed her in the back, very detailed. - and she tells me I don't know what they are doing to her. That the aides come in her room and lay on her bed and watch tv. 5 months ago she thought I was trying to kill her. We had all kinds of tests run and she was okay. The home has tested for UTI. She isn't on any medications and refuses to take anything. She asked that I bring her peanut butter and 3 pieces of bread and to not open the jar.