JSFiddle - React, Tailwind, and code Playground

HTML

<iframe id="frame" width="300" height="300"></iframe>

JavaScript

$(function(){ 
    var createScript  = function(url){
		var s = document.createElement("script");
		s.type = "text/javascript";
		s.src = url;
		return s;	
	};
    //colocando jquery no iframe
    $("#frame").contents().find("body").append( createScript("https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js") ); //adicionando jquery
    
    var iframeWindow = $("#frame").get(0).contentWindow; 
    console.log( "IframeWindow width: " + iframeWindow.innerWidth ); // imprimindo largura do iframe
    console.log( iframeWindow["$"] ); //tentando recuperar instancia do jQuery
});