adding a button for additional children on PDF converter

Hi I'm trying the new pdf feature and would like to add a button to "add more children" if needed oppose to keeping the form very long with the child 3, child 4" options is there a way I can add a button that will auto populate another set of information for additional children?

You can try the Configurable List widget on the form.

But, please note that this will not auto-populate data. You can have the "add button" to add new rows to add additional child data.

Here is how you can set up the widget: How-to-Set-Up-the-Configurable-List-Widget 

Let us know if that will work for you.