Does an 8-year-old really need the filet?
While it's always nice to be able to offer your guests a choice of entrées at your reception, finding out what they'd like to eat is an extra detail you need to keep track of as RSVPs roll in. Offering a kids' meal can complicate things even further: The option isn't usually included on RSVP cards, which means you'll need to get in touch with any guests with children directly to figure out whether their kids will want a children's or adult's meal. And then there's the cost! That filet is definitely pricier than chicken fingers, and it can be hard to accept that your cousin's seven-year-old will enjoy (or finish!) the fancier dish. So are brides and grooms allowed to decide all kids get the kids' meal, no matter what?
Source: Can We Just Decide That All Children Get a Kids' Meal at Our Wedding? : Brides