​

var currChild = 1;

​

function getChildDivHtml(id) {

  return '<div id="child' + currChild + '">Child ' + currChild + '<button class="btn-add-siblings">Add Siblings</button></div>'

}

​

​

$(document).ready(function() {

$('#btn-add-child').on('click', function() {

  $('div#parent').append(getChildDivHtml(currChild));

  currChild++;

});

  $('div#parent').on('click', '.btn-add-siblings', function() {

    $(this).parent().append('<div>Sibling</div>');

  });

});