Where do the thoughts of an educated woman go when she no longer speaks?

How can I share in this life altering experience to sooth our anxiety? I am the only girl of 5 and the youngest. I was told my whole life I would be needed to care for mom in her golden years. So... I did whatever and waited for the time to come. In 2010 mom needed heart surgery, dad has been sick with Parkinson's for years. I quit my job, cashed my 401k. I slept on the floor at the ALF to help with dad... Now on hospice 2012... and help mom adjust to community living. Dad passed 5-2014. ALF let me stay another 6 mos then wanted to switch mom to NH after minor fall...just bruises. A PRIVATE ALF picked up moms application and she moved in. During the one year there she quit using phone tv remote, reading (a librarian her whole life) She lost interest in everything. I was visiting almost everyday and doing activities with the whole group to try to fit in. My siblings ( the boys ) were visiting twice that year. So...i talked with my BF of 20 years and he agreed mom should come live with us. Feb 1 2015 Mom came here. She had also lost the ability to walk after a UTI and Parkinson's Balance issues. She was mentally with it but still not interested in much. There was a few good moments she couldn't help be part of, but most activities were rejected. The boys visited more...
Today she is bed ridden and looks at me with blank eyes and rarely responds. She had a bad UTI that landed her in the hospital twice in 3 weeks. The 2nd time they sent her home on oxygen and hospice. They thought a week maybe. She got much stronger once back home and it has been 6weeks. She got another uti ( which are complicated by kidney stones ) . It has only been a few days after finishing the antibiotics and I'm sure she has another. She has refused her meds and sleeps most the time. When she wakes up she doesn't know where we are. She has quit talking and as of last night. Can no longer tell if she has had an accident.
I am whole heartedly into caring for her til the end...promised her I would. She and I talked after dad's passing and we were going to do hers better...together...im afraid the days of her sharing stories and making choices are over. I thought I would be better prepared emotionally. I thought this would help me get over my dad..haven't yet. I'm rambling...my question is... can she not express her thoughts or are there no thoughts? Sometimes she looks like she wants to tell me she's dying but not a word. Id love to talk about heaven and the next journey but not without her participation. I'm stronger than I was with dad but I'll never be ready. Mom is 92 and had a storytale life with my dad. She is tired and her body is done. I want to comfort her emotionally but she seems to look the other way and not acknowledge our situation. Soon it will be too late . What can I do? Am I selfish for being so curious? It is hard to face life's fact but I'd rather grab it by the tail and share any hopes or fears..