QQmlListProperty is a very important type for types exposed to qml. It is the only way I know to allow declaration of multiple child in a parent:

MyClass
{
    MyChild{}
    MyChild{}
    ....
}

Currently I found a workaround: expose MyClass as MyClass_ with a 'QVariantList' property and create a MyClass.qml type with a qqmllistproperty, but it is a PITA:

import QtQuick 2.5
import ...

MyClass_
{    
    default property list<MyChild> childs_;    

    childs:
    {
        var l = [];
        for (var i = 0; i < childs_.length; i++)
            l.push(childs_[i]);
        return l;
    }
}