Many employees don't get a "lunch hour" where they can leave their jobs and they are not provided lunch. In fact, I've never heard anyone other nannies even bring up the idea that they deserve free meals.

Nannies can bring their lunch, like everybody else, unless they wish to negotiate this perk into their contracts.

Nannies don't get a "lunch hour" where they can leave their jobs and go to a restaurant. So yes - lunch should be provided by the employer.