When a LO is diagnosed with dementia and mental illness, what is needed to make DPOA revocable, even though it was valid for use when created?

My LO has a friend that is urging her to change her D.P.O.A., and remove me as D.P.O.A., because my LO has misrepresented me to this friend. And, the friend believes every word my LO says, and starts stirring the pot, so to speak, with my Mom's fixed delusions that I don't have her best interest. I do have her best interest, and I have never done anything against her or to hurt her. Her paranoia and all of a sudden thinking I am being unscrupulous doesn't make good sense. I have never used her funds for any of my own expenses. I keep all monies separate from my husband's and my funds. I don't know what has set my LO off to all of a sudden start thinking that she cannot trust me, except that her dementia combined with her mental illness is progressing.

Anyway, instead of this friend trying to talk with me, and help me help my LO; she does the exact opposite and works behind my back with my Mom to encourage her delusions, and tells my Mom that I am selfish, conniving , and out for myself, and because she believes everything my Mom says, without knowing what is true, or not, about my LO's paranoia and made up stories to her. She doesn't believe my LO has dementia or mental illness, and has convinced my LO that since I have DPOA and health care, and medical directives, and I am on her living will that I have cohersed my LO's doctors into believing she has dementia and mental illness because my LO doesn't think she has it, either. Which is irrational within itself, because my LO has taken several cognitive tests with three different specialist, and dementia has been diagnosed by all three. And two Drs, also diagnosed her with mental illness, too. She is taking medication for mental illness and two Alzheimer's medications. My LO is still intelligent, and I think that is the reason my LO and her friend thinks she doesn't have dementia. And, my LO is excellent at masking her problems. And, she can fool people that don't know her, or that are not around her too long, that she is fine.

If her friend does take her to a lawyer to change her DPOA, can her current D.P.O.A. be revoked since her dementia diagnosis is in her medical records with pcp, psychiatrist, neurosychologist, and neurologist? And without me having to file for Guardianship or Conservatorship? And that other DPOA would be null and void, and the original D.P.O.A. would still remain intact? Correct or Not correct? Thank you for your time.