What can one do to stop a verbally abusive sibling from coming over to see mom who lives with me? During these visits she tells her things about me that are not true and upsets her to the point where she is now needing more and more anxiety meds. This sibling also texts me calling me vile names and making accusations that I'm stealing her money. I'm at my wits' end.
Most likely, professionals may not believe you as people who carry out this abuse will deny everything and claim that they are the victim of your abuse. They can be very convincing. You may even be accused of abusing your mother so the key is to know what you are dealing with. My sympathies to you as my own sister and her husband abused my mother in this way and convinced professionals and mum's family that i was the abuser. It is truly evil to treat anyone, let alone the elderly in this way.
Id still block her from your house if she can't be civil. You and your mom don't need that stress.