First off, it absolutely sucks when you're fed something that isn't veg*n. I'm sorry that happened to you, but don't worry too much about it. Just chalk it up to lesson learned and move on.
Second, you can argue back and forth about whether or not 16 is a kid, but the bottom line is this...
Kids are not responsible for their own food. Their food is prepared for them and they eat it. If they don't like it, they can typically go make a PB sandwich, or some cold cereal, or go to bed hungry.
Adults are responsible for their own food. They prepare or purchase food according to their preferences, dietary, flavor, etc... They can get cookbooks, and browse the internet, and take cooking classes, and experiment and learn to cook.
You cannot be both. If you are going to make the decision to be veg*n, and the rest of your family is not veg*n, then you need to take some responsibility for your own nutrition. Granted, yes, the housekeeper has been hired to look after your family's needs while your parents are not available, but I don't believe she's been hired as your personal chef. Caring for three young children, and a household is a LOT of work. Housekeepers/child care providers are never paid as much as they deserve, even if they are paid "well." She obviously has a poor understanding of veganism, and it would probably be better for all parties involved if you prepared food on your own, or found a way to work with her (and her not work FOR you) in preparing your meals. Maybe if you said you wanted her to TEACH you she might be more receptive to having you in the kitchen. On the other hand, it sounds like she has plenty of responsibilities and may just need to get the little one feds as quickly as possible.
So you've got some thinking to do. Are you an adult? Or are you a child? You can't have it both ways.