I was 2.5 years old when my brother was born with complications, brain damage being one of them. Could breathe by himself, but fed through a tube and couldn’t move. 3 months later he died.
Not sure what the total impact from this event has been, but I am affected by this event even today, decades later. It’s weird how something can impact a little child that much, but the loss was/is real. Especially with kids that I played with that had siblings (at that time when I was back to zero). Not unfazed, but not mentally crippled either. My parents didn’t, unfortunately(?), take me to any counselors or so, it wasn’t even recommended by any in the medical support apparatus.
I am often reminded that “God gives and he takes” (especially Job’s book), that might be the most pragmatic approach I’ve come up with over the years. And I still miss him when the wound opens once in a while, but at least he didn’t have to suffer.
I haven’t finished the books yet, but C. S. Lewis has at least two on this topic: “a grief observed” and “the problem of pain”, the latter written before losing his wife to cancer.
I hope you and your family can come through this trying time with your hope and faith intact.