In my family we have always discussed our financial situation quite frankly between adults.
Not to the extend of viewing each others bank statements, but certainly to the extend of knowing whether parents, children, siblings or whoever were living comfortably or in debt.
My parents outlined their intentions regarding their wills to my sister and myself when they retired and we were both young adults. As they had a joint will, I asked my father when he after my mother's death said he would need to make a new will, that he either told us both the provisions or told neither of us, as I felt it was unfair if he only discussed his intentions with one of us. He agreed and subsequently only mentioned that he had made a new will and who his solicitor and executor was.
A power of attorney for the eventuality that we should become incapacitated is, obviously, a matter of trust. Again there, I asked my father to join my sister and myself in one, as I said truthfully that my sister would neither cheat me, nor accuse me of cheating her, but I did not want if he had chosen to give me the POA that her children and their spouses could look askance at the arrangement.
We avoided that pitfall, but when my sister died my suspicions regarding her children and their spouses proofed wll-justified.
If you either do not have children, or know that your children will be unable to agree whatever you have stipulated, I think you would be well advised to give a POA to some other responsible person, but this is a matter where you need legal advice.