Sure, if that’s what she clearly indicated as her preference at a time that she was in full control of her faculties. And I would get great personal satisfaction from knowing I assisted my mom do what she strongly wanted, when she was incapable of doing it herself.
And not wanting to be a burden is just a part of my reasoning. My self image is as a reasonably competent individual. If I get to the point where I lack BOTH a certain degree of mental AND physical capability - well, that is not a person I wish to be. That is not how I wish to be remembered. That is not an existence I want any resources - mine, my family’s, or society’s - expended upon.
I acknowledge that I have a prejudice towards people who are - in some way - capable of contributing, or are at least independent. Many might think that makes me a horrible person, but that is who I am. Other people are free to make their own choices. I’m not advocating killing of people below a certain functional standard, just expressing my preference that I don’t want to be such a person. I’ve had 56 years of reasonable competence, and I firmly believe that this life is all we get. Sure, I’d like to live to be 100 (if in reasonable health) - but have no interest in lingering beyond a certain point.
I don’t understand YOUR position - if I can’t count on my family, then who can I count on? If my society would permit medical-assisted suicide, I would have no need to ask this of my kids.
If your mom asked you to help her overdose when she reached a certain point, what emotions would you feel from taking any measures to extend her life beyond that point? I would rather have my last memory be of assisting my mom in a huge and personal way - rather than recalling an extended gradual decline to the point at which the shell in the bed bore no resemblance to the person who had been my mother.
As Tzigone observes, it is unlikely that a pillow would be involved. As my son, the engineer, helpfully observed, “Most pillows lack sufficient density such that too much air would get through. But I’ll take care of you, dad!”
I imagine the most likely would be amassing sufficient meds (or scoring illegal drugs) to assist me in ODing on.