The sounds like a common problem.
My Dad recently died and my sister had power of attorney for 14 years, and I’m pretty sure that she skimmed, which is of course a violation of her fiduciary duty.
I thought about looking into it; I just don’t want to destroy my relationship with her. And she did do a lot for my dad over that time; she was there with him, changed nursing homes several times, found caregivers, while I was up here, not able to do anything.
We’re still in the process of this. It’s sad how money can tear families apart.