I would like to hear from anyone who has had experience with an ALS patient on the ventilator. My mother (73 y?

I would like to hear from anyone who has had experience with an ALS patient on the ventilator. My mother (73 years old) was diagnosed with ALS 3 1/2 years ago. The past year she has lost all her movements one after another for 8 months (everything real fast)and has been on the ventilator for the past 5 months. My mother has been unable to communicate for 3 months and I know in my heart that she is tired of being a prisoner in her own body that no longer serves her. This has been a long battle and I am just wondering how much longer will she have to endure. If anyone has any information that would be helpful or informative it would be greatly appreciated. I love my mother and I see that she is miserable. We are ready for her suffering to end .