Option 1: Meal Preferences
The easiest option (and usually our recommendation) for adding kid's meal options is to simply add them as options to your meal preferences section under Setup > Meal Preferences. You can clearly label them as such so guests know they are meant for child guests only.
Option 2: Custom Questions
Some hosts prefer to use the custom questions feature to request meal preferences. The custom questions allows you to select from a variety of formats for your question such as multiple choice, as opposed to the meal selection dropdown. We recommend adding all meal preference questions in the same format (i.e not adding some options to the meal preference section and others as custom questions). So if you are adding kids options you may want to add them here as well.
Option 3: Secondary Events + Custom Questions
If it is really important to you that kid's menu options are only shown to guests that have children attendees, you may opt to use a secondary event to restrict the question to only guests with children. You can follow the steps in this article to learn how to use secondary events to use secondary events to ask conditional logic questions.