$("p").each(function(){

    // Add a div after the second <br /> (in the current <p>)
    $("br:eq(1)", this).after('<div class="theRest"> </ div>');

    // Split each "child" in an array
    $(this).contents().filter(function(index, elem){

        // Keep only children after the <div />
        return index > 3;

    // Remove and put them into the <div />
    }).detach().appendTo($(".theRest", this));
});

$('p').each(function() {
    $(this).contents(':gt(2)').wrap('<div class="theRest"></div>');
});

$('.father').find('p').each(function() {
    $(this).contents(':gt(2)').wrap('<div class="theRest"></div>');
});

$($("p").contents().get(2)).after('<div class="theRest"></div>');
$("p").contents().filter(function(index, element) {
    return index > 3;
}).detach().appendTo(".theRest");

var txt = $('.txt').contents();
txt.splice(0,1);
txt.wrapAll($("<div>").addClass('red'));