Which way to indicate child? isChild or child?

[creduo]

There's two way to indicate a passenger is a children,

in Air/Services/transformer/add-meta-passengers-booking.js

      item.isChild = true;

in Air/Services/transformer/convert-passengers-object-to-array.js

          child: (ageCategory === 'CNN'), // quickfix

This makes really confusing, to them or to implement other features. Can you sort them out?