To be or not to be?

A 66 year old woman heart disease, diabetes, hypertension with end stage renal failure and bilateral above knees amputation collapsed while having her regular "3 - 4 hours a day, 3x a week for the rest of her life)" dialysis.

The paramedic were called in and quickly intubated (LMA) her, and she ended up in ICU.

The 'morning-after' had lotsa docs debating wheather intubating her and put her on life-support was the best course of action.

After all here is a person who have multiple chronic medical problems with no legs, now in semi-vegetative state depending on a life support machine.

Question:
Is it necessary to prolonged her life in this sort of manner?

or should the gung-ho emergency personnel let her slipped away peacefully following natural course of life & death.