Here is a video of healthy veggie-kids! There is something very different about vegan children. The video below is about parents raising vegan kids:
I raised Josh vegan and he's 6'3" tall now and very active. He's 20 now and has become an excellent vegan chef, specializing in decadent cake recipes from scratch, that even our friends who eat meat say are the best they've ever had in their life! (And no, you should not eat cake every day, but indulge once in a while if you feel like it).
Feed them raw, delicious food, and always have a large variety of fruits, vegetables, nuts and seeds for them to choose from. Kids will not starve themselves, so as long as you have a lot for them to choose from it will go very smoothly :)
I would suggest staying away from soy products as much as possible because they tend to be overly relied upon and can cause health problems (I have soy sensitivities)... Don't worry though- there are incredible recipes all over the place that are made without soy.
Massive soy mono-crops are taking over land that could be used for greener crops, and there is a major problem of clear-cutting forests to replace land that has eroded and lost all of it's nutrients in the topsoil as a result.
I ABSOLUTELY recommend you raise your kids vegan- Josh never gets sick- it's not a myth- vegan kids are healthier. There is nothing to fear so don't let people get to you. Love your kids? Love the planet? Love yourself? Go vegan!