I've been vegan for 10 years and have two healthy vegan kids (with a third on the way).
From a nutrition perspective, I have no worries. One child is fussier than the other, but both have reliable protein/fat/carb sources I know they'll eat. They don't like many vegetables yet but they love their fruit! I give my kids a daily multivitamin (Vegetology Kids) and a daily omega (Vegetology Omega orange liquid) - they LOVE taking these after breakfast so must taste good, and then you can feel reassured they are getting the things that are harder to get from vegan sources (B12, iodine).
From a social perspective, I was worried when my eldest started school that they would feel excluded or different, but they're at a small village primary school (60 odd kids in total) and there are loads of other children who are dairy free, one who is gluten free and two with severe allergies to obscure things, but it means there are other kids with their own dietary requirements so they don't feel like the only one. Honestly, no one has ever been negative about our kids being vegan at school/play dates/parties (to mine or my child's face at least!) and there are livestock farmer's kids at our school! I always offer to provide food at parties or a haribo alternative for the party bag, but usually the other parent says it's no problem.
A PP said something along the lines of you should let your children choose veganism when they're older. My partner and I have discussed letting our children choose not to be vegan when they're older, and are aware this is a decision they may indeed make for themselves, but we think until then it's a parent's responsibility to make what we believe are the right choices for our children. If veganism feels right for you, surely it's right for your kids too.
I do think raising kids vegan from the start is easier than transitioning them to veganism though. My kids don't know any different, they ask if food is vegan before they'll touch it! They (sometimes awkwardly!) ask people why they aren't vegan, and why they kill animals to eat them! My friend who became vegan a few years ago has not successfully managed to make her now 8yo vegan. They're vegan at home, but make their own choices at school. Maybe this could work for your family?