They did! The company Huntliegh got her off the flight then left her on her own.
More here:
https://www.kxly.com/news/spokane-family-sues-alaska-airlines-for-mothers-escalator-fall/678606175
You keep sniping at people to read the article.
Perhaps YOU should do a better job at excerpting and posting.
The family did not indicate that they needed assistance upon purchasing the ticket. They did not check the boxes.
If she refused assistance after getting in her powered wheelchair, she is then on her own. It is the fault of her and her family, not Huntleigh nor Alaskan Airlines.