Is this a trick question?
Here's a trick answer: it depends.
The making-your-own-lunch thing is a pretty big part of the Box Lunch Lifestyle approach to food. So, what is it that's important to you about making lunch for someone else? How are you helping that person? Any chance that "helping" could actually be "replacing something that would feel good to that person or help that person learn"?
How about this suggestion from Box Lunch Lifer Lisa G. instead: exchange homemade lunches with a coworker or friend. That way, she or he still gets the pleasure (it's true--you'll see!) of both making a homemade lunch and eating one. Just imagine the potential for memorable lunch food and conversations.
It sounds like a sneaky and totally FUN way to hold each other accountable.