I was raised with three non-biological elder siblings. I wish I could tell you they meant well. They didn't.
Harold, the biological father of myself and Brad, had purchased a number of cemetery plots in Kzoo. The number was calculated to include my then extant mother.
Five decades later, Brad was in hospice. He'd refused sustenance. His home care was managed by a person whom I could think of as my third mother. That is how sincerely she had Brad's best interests at heart.
My best "educated" sister would often berate me for not telling the entire truth.

Absolutely. That makes perfect sense. A Washington state Realtor is the obvious choice to prolong our Father's agony.
When Brad was in hospice

at least two of the three got the idea that this was a financial opportunity to undermine Our Father's bequest of his entire estate to my third mother. Brad, at that time, had less than five figures left. Maybe 4. If that. Sisters thought that if they could get His care transferred to them, they might alter the bequest.

In Japan, one does one's own headaches. How are your migraines now?
In His Will, he was very clear. He wished no funeral. Even more clearly, and protected by law, He indicated His entire estate to go to my third mother. After his purported passing, the eldest did an extraordinary job as executrix. I requested a DNA test. She refused. With respect to His financial bequests, she was just a Wii bit less diligent.