You can use RSVPify's Custom Questions feature to ask guests for their meal preferences for your Secondary Events.
To add a custom question to a given secondary event, follow these steps:
1. Open your event.
2. Select Setup.
3. Select Custom Questions.
4. At the top of your screen, locate the drop down menu. 'Primary Event' will be selected by default. Select the event you'd like to add a custom question to.
5. Optional: enable the question setting "Only ask question to guests indicating they are able to attend"
6. Save your questions.