Can you remove someone as medical power of attorney without their knowledge?

Yes, it can be done without anyone's permission except the great grandmother as long as she is competent.

Second what Jessie said. Note that the grandmother (or anyone else) cannot make the decision to add herself. That is totally the responsibility of the great grandmother. She can add whoever she wants to - if she is competent and they cannot be removed. If she is not competent it no one can be added. If someone has been added and the great grandmother is incompetent, your friend better see a lawyer.

Are you saying as DPOA, Medical POA and executor, that I would NOT be notified if it had been changed?

Innerchild, I don't think you have to be notified; but personally I can't see the earthly sense of not telling somebody if you won't require them to act for you, after all. I suppose in some families it might result in harsh words and high feelings which the donor of POA might want to avoid, and is entitled to avoid. Is this something you have reason to be concerned about?

Thank you for quick response, Churchmouse, I more than appreciate it. I feel YB has 'poisoned' family and family friends and Gaslighting me so he can take control. I just recently asked OB and others 'what is going on?'- to be honest, but no answer or been told I'm imagining it. He has done shady things when he divorced his wife. He looks like the 'good guy' and I look like the bad sister, as I keep to myself. My mother is 93 1/2, and still doing well mentally and physically, but a lot of dysfunction in family. I don't know who to trust, and yet it hurts terribly to be ostracized. I know in my head people like that are toxic and better to avoid, and read posts here of similar situations. Thank goodness for this site, as I go to counseling, but I already deal with abandonment issues, anxiety, Fibro, etc. I already wrote more than intended.

inner child, as I understand it, there is no legal requirement for you to be notified, but it would be a courtesy. Family dynamics can pay a part as cm mentioned. If it is now a dual responsibility of your friend and her grandmother, they need to be able to work together to look after great grandma's best interests. Now not sure from your last post if this is about you or your friend.
I suspect of anyone was removed in any capacity they would be informed, but I don't know for sure. For myself I was sole POA and then my mother wanted it to be dual with my sis and I both. I refused that arrangement and said if she wanted my sis on as co POA, then I would withdraw It would have been a nightmare. So she listed sis as backup if I could or would not do the job. I would check with the attorney who drew up the documents to see what the terms are.

Well, the thing to do is to ask your mother about it. Because for absolutely certain, her POA instructions cannot be changed without her explicit, informed, active consent. So she would know. And since she picked you in the first place, I can't imagine she'd be happy to make any changes without involving you at the very least.

Your brothers - whoops, did I type 'bothers' just then? Freudian typo?? - can machinate to their hearts' content: as long as she's competent this is your mother's decision, and once she is no longer competent POA can't be changed.

Don't get paranoid, by the way. I don't mean you sound it, it's just that I quite often felt it when my siblings were getting on my nerves.

Thank you Churchmouse and golden. My mother changes moods quite often, depending on who is doing what she likes. I.E., going to Tx for Thanksgiving 10 days, when last year (and another time) she vowed it was 'the last time'. She ends up paying for trip and all the food. It's her $, but this is how YB golden child manipulates her. I am trying to detach, as it's all his entitlement issues. Yep Church, it REALLY is stressful. I have asked her if anything changed and she said 'no'. I need to call attorney next week.