Quick question for the vegetarians, vegans and the like...

I am in the middle of writing a cookbook and would like to include some tips for parents of children who have declared they will no longer eat food with faces. Whether it's nutrition, the meatless recipe that you cooked 3-4 times a week at first, or the delicate handling a child who seems to be rejecting your lovingly prepared meal, parents need help with this. So, two simple questions:

• If you could some advice to the parents of a newly vegetarian/vegan child, what would it be?
• What is the worst thing you can do if your child decides to eat a meatless diet? (Personal experiences from hell are welcome.)

Thanks for your contributions, everyone.