Someone in my social circle is vegetarian, but doesn't eat eggs. Also, they only have vegetarian cheese (I thought most cheese was vegetarian now?), and don't give yogurt as that's often not vegetarian? I thought yogurt (unless it has gelatine as a thickener?) was always vegetarian?
She's keeping her son vegetarian, with the same rules, which just seems really difficult. He can't have birthday cakes (eggs), or normal food with people, really ... is this a common thing to do?
(Most of the vegetarians I know either don't force their kids to be vegetarian, some even cook meat for them (!!). Or they are vegetarian, their kids are vegetarian ... but not vegan ...)