Your question reminded me of the death of King Saul. He wanted to die, because he had lost the battle and all hope of surviving, and ordered his armor bearer to kill him and yet he refused. Saul then fell upon his own sword! An Amalekite who was passing by, saw that Saul was not yet dead, and Saul let him know, by a verbal request, that he wanted to die now, and not suffer any more. The Amalekite obliged the King. When he told King David what he had done, David had him executed for the murder of God's annointed.
So according to 1Sam. 31 and 2Sam. 1, even if the King wants to die, and begins his own suicide, and asks someone to finish his job for him, and he does , that person is still guilty of the shedding of blood. How much less validity would a written directive from a woman who is not the annointed {KING} of God, have if one were to help her carry out her wish to commit suicide, in a condition from which she is not dying?