[IYAS9YAS]

then when it becomes unbearably hot the child wakes up due to the extreme discomfort and struggles to escape until the child finally collapses exhausted.

I don't disagree. My thinking here is that she may have been disoriented and too weak to crawl to the door or open it to get out. The Sedonas didn't all have auto doors where you could push a button for the automatic door to get out. The door may simply have been too hard to open in the child's weakened condition.

[1_Rain_Drop]

Maybe she did try to get out of the car but couldn't because of child safety locks on the back doors. The doors could only be opened from the outside.

Little angel, RIP.