My Mom had scleroderma, a very rare form of Lupus. The disease that tightens the skin and makes sufferers appear to have a "monkey face". In some, it also slowly hardens the internal organs... basically turns them into stone. She had both.
My Mom fought the fight for a long time. They gave her 5 years, she made it 12. However, in that last year of her life, I got pregnant. After 13 years of marriage without being able to get pregnant - I got divorced, met someone else and got pregnant. My Mom knew that there was nothing more in the world that I wanted, but to be a Mom.
The timing, couldn't have been any worse OR any better. It was a double edge sword, so to speak. She was so sick but I knew my news would ultimately make her happy. I also knew that the initial shock might be bad for her... here I was... divorced, on my own and pregnant at 37!!!
Anyway, it got to the point that I had to tell her because I was starting to show and she was slipping fast. It was difficult to catch her out of the hospital. I did tell her one afternoon that she was home... her sister and SIL were on their way over and I knew that their excitement would help calm some of my Mother's fears.
So, I told her and my Father. Once her Sis and SIL walked into her bedroom, realized what was going on... it was nothing but sheer happiness for her. She knew that I wasn't going to be alone. She knew that my DS (now almost 7) would bring a ray of sunshine to our first Christmas and it was almost her "ok" to let go, give up the fight.
I never once told her to hang on for my son. I never once told her I needed her to be here for "ME". I shared all the details of my doctor visits, showed her the ultrasound on video and she helped me name him. When she started to give up the fight... it was about 3 weeks after I told her and I just sat with her and let her know that we, my son and I, would see her someday and to wait for us there.
It's an individual's decision and I think that most make it with a full heart when they decide to just let go. Give her support, either way that she decides. Know that if she is tired and ready... it's not because she doesn't love you or want to continue to be with you. She'll always be with you. I see my Mom, every day... in my DS's eyes.
I let go, so she could. She died when I was 5 months pregnant and I'm grateful for the time we had together. I wish you all the best during this difficult time and please feel free to PM if you need to talk.
My thoughts and prayers are with you.