Can a person under G/C change their designated trustees for a revocable living trust? Can they choose to revoke that trust?

Yes, Mom signed it and I guess the lawyers were the witness and notary then...

Lawyers don't sign trust amendments; they can witness and notarize, but the individual who made the trust (the "Settlor") has to sign.

Well, I have a guardianship and conservatorship order with no exceptions, yet today I got in the mail a new will naming me as executor, and an ammendment to the revokable trust signed by two lawyers making me trustee and disinheriting my sisters. I did not originate this, but I allowed my mother to meet with her lawyer and this is what happened. I felt that I did not have the right to deny her representation. Guess now I need another (better) lawyer to sort this out again. None of it seems legal to me, common sense prevailing.

If she has dementia, and the doctor has already written a notification that she is NOT competent, then she cannot make changes to her POA, Will, or Trust. I'm not a lawyer, but this is common knowledge--once they've been "labeled" incompetent by their doctor, it would take several other doctors to examine her and declare to be competent, and usually doctors don't want to overrule each other.

Forgot to answer the second question as to revocation of the trust. Setting aside the 2 contingencies I wrote of, a revocable trust can be revoked by the settlor/maker, but a new will would have to be created because pour-over wills are designed specifically to dovetail with a trust. So she'd have to be legally competent to enact such a revocation.

What is the basis for your being your mother's Guardian and Conservator? If it's dementia or a form thereof, I think an attorney would be hesitant to make changes in the Trust and ancillary documnts.

In addition, it does sound as though your mother might be experiencing a temporary hostility toward the one daughter. If this is reversed, then changes might have to be made again.

Any maker of a revocable trust can change it by virtue of a restatement or amendment, if that person is of sound mind. I honestly don't know how changes could be made though if any dementia is involved. That's definitely an issue for an attorney.

I'm not sure what issues there would be that a "burden" for a trust change is not as high as that for a will. Codicils to wills can easily be made. Actually changing a trust would probably require changing the pour-over will too, as well as any certificate of trust existence and authority.

Maybe I'm missing something in the interpretation though.

The trust must have provided specifically for automatic authority switch to the designated successor if lack of financial responsibility (or other conditions) were specified. However, I'm a bit curious to whom this letter was directed, as your mother as settlor/maker of the trust would have theoretically been the one to whom such a letter was addressed.

There really are 2 unknowns and possible complications in this situation:

1. Whether your mother has any dementia, and

2. The scope of the guardianship order and what powers were created, and that's not an answer that anyone can provide without knowing the scope. You might want to reread it carefully to determine if there is anything in the Order that speaks to your mother's authority to effect changes to legal documents.

In a revocable trust, there is no burden at all. She can change it any times he wishes.