As if this weren't obvious, but apparently, you are the master of not understanding the obvious. There's a HUGE difference between this mother being content with the offerings MADE to all coach passengers, and demanding/requesting that she be given some sort of special treatment by getting a first class meal designed and offered ONLY for that class of passenger.
Sheesh.
Obviously, airlines are free to make whatever food and beverage options they choose to the various classes of passengers, but to demand that something destined for another class be offered to you, well, that isn't going to happen and it's not reasonable.
I will go back to another example. Let's suppose I have a medical condition where I cannot sit for long periods. It's better for me to lie down. Now, I opt to take an overseas flight of 14 hours. I'm cheap. I book coach. I can't possibly sit for 14 hours. I guess in your world it would be right for me to either demand a first class sleeper seat (to 'reasonably' accommodate my disability) OR be allowed to lie in an aisle...heck I'll even move when the carts come by. Surely, there isn't an issue with that right. I need it. It's available. Why not.