I know I said, "Thanks ahead of time for any condolences and well wishes," but thanks again, really. I appreciate every single one of the responses in this thread.
To add a bit more, as crushing as this continues to be, it was time. Mom was not getting any better, and had been saying for weeks that mornings (right when they'd wake up) and evenings (getting ready for bed) had become a nightmare for both her and my dad, who was her caretaker. I never said this until last night when talking to my dad, but for weeks I had been thinking, "Please don't let this get to where Mom has to go into a nursing home." I conveyed that thought to Dad last night and he was in agreement. Now that we don't all wish she were still here, but I think you all know what I mean.
My grandma (on my Mom's side) passed away in 2013 at the age of 103 and she spent the last 10 years of her life in a nursing home, and I wouldn't wish that on anyone. My mom pretty much went to see her there pretty often (probably every other day) when she could for those last 10 years, and I know she would not have wanted to end up in a place like that. So, I am very thankful that it never came to that.
She went at the right time. And we - me, Dad, my brothers, her two still-living brothers (my uncles) both of whom are in their 80s now - were all at her side when she finally let go peacefully.