Typical media over-hype and AA caving to media pressure.
She was taken to the airport by her son who had another flight to catch and thus dumped her at her departure gate, but her flight was cancelled.
Turns out that the woman not only requires a wheelchair, but is barely able to communicate. She was offered a hotel, but the wheelchair pusher contract does not include delivering pax to hotels (nor would a sensible hotel accept a person in the woman's condition).
This was 100% on the son for abandoning his mother. AA does not provide caretaker service and the wheelchair people are minimum wage contractors who provide a limited service and are not caretakers themselves. If she had turned up somehow at ORD on her own, I doubt that she would have permitted to proceed.
The only AA fail here is in not assuring that someone who is not capable of traveling alone, as this poor woman clearly was, is accompanied by a properly ticketed passenger. The fact that the son's ticket was to a different destination is a good reason to presume he would dump her at the gate.