In all my years, I have seen about a dozen lowbeds high centered, or bottomed out. 3 of them I helped get out, by merely disconnecting the air ride height valve rod (held in place b y a rubber bushing), and letting the system fill the airbags to max. Many trucks have dump valves to dump all the air, and lower the truck, I never understood why they would not also have a max valve to raise the truck, and another on the trailer, for the lowbeds. I have seen some extra heavy duty low beds with a valve to raise the bed, but it was in a spot that the drivers likely did not even know it was there, or what it could be used for.
I hope your Wife is able to move on. I know how some of the simplest seeming things can hang on in ones memory.