Hello (M), this is Patrick.
From your point of view it seems a long protracted end to your mother’s life. But you need to understand that because, in reality, the way you measure time is not how other Worlds would measure it. The life and death of a Soul is very much an arbiltory matter. A human mind is so limited in understanding Spiritual matters and is totally inadequate.
Your mother has stayed alive for so long for a specific purpose. There really is a reason for everything. (M) – at the moment you are too involved with the Whys and Wherefores and therefore not able to see the reason, but you will see it. You and your son are the ones most affected by this – let your mind become empty and you will see why.
You need to change your attitude. Don’t think, “Why is she living so long?” Be thankful that her existence is important so people can learn and grow.