My sis had my 92 yr old mom sign a bogus will which left everything to her, instead of my son. She is in MD, we are in GA. What can we do?

You seem to be describing a Power of Attorney, not a Will. PoA acts as a legal decision-making agent for a person. You info makes no sense. Maybe your Mom realized she needs an agent to help her, and in this case she chose your sister. You will need to prove that this document is "bogus" or she was somehow cognitively incompetent when she signed it. However, the notary and witnesses possibly would have flagged this if this were so. My Mom downloaded a PoA form from Legalzoom.com to assign me. Had it signed in front of a notary and 2 witnesses. Perfectly legal. The legal burden is on you to prove what your Mom did isn't valid.

A Will is for when she passes away. The Executor of the Will is in charge of carrying out her wishes as specified in this legal document.

I just read your profile. It’s very interesting. Your mom lives alone, has dementia and is a legal gun owner? What?????

You state in your profile mom lives alone and doesn’t see anyone. Obviously, she has contact with your sister if she changed the will.

You don’t even speak on the phone with her. Do you ever see her? Does your son see her? Why is she living alone with dementia and a gun in the house?

There are at least two sides to this story, yours and your sister’s side. Possibly three sides, the actual truth in the matter.

I am thoroughly confused but I do hope that things works out for the best.

Please remove the gun from your mom’s house if she has dementia!

It would of course be necessary, if you contest this will, to PROVE both that your mother was incompetent (which is legally different from demented) to sign a will at the time she signed it, and/or that she was "brainwashed" as well.

You state you were estranged from your sister. Were you ALSO brainwashed from your mother? Did your mother tell you she was changing her will? Did this sister live by/with your mother and care for her?

If you have proof of incompetency at the time the will was changed and of "brainwashing", you can take that proof to an elder law attorney and attempt to contest the will. Do know that if you lose this contest the may be accountable to court costs of the estate as well as your own court costs.

That's about it. You may want to consider if it is worth it. For myself, the disturbance to my peace of mind would preclude such a thing, and I would get on with my life.