If you run classes or events for children, your customers (the parents) may wish to book more than one child onto your sessions.
You can do this by adding a Sibling Extra to your Price Bands.
The same process applies if you wish to allow the customer to allow another person to their booking who will take up another place against the capacity for the event/class.
The video below walks you through how to create the option to add a sibling to a booking.
Note: If you don't want the extra person to take up a place against the capacity for the class/event, you should add the Extra as a product.
Related:
Use Extras to sell products or upgrades to bookings