Get head of a page (with your url)?

Working on a project I had a problem in which I have to get the head of a page (it is not the head of the page on which the js is running)

I explain myself better

I use the AEM CMS, so all the pages are based on templates, there is a section of the site (parent page), where the content of other pages of the same site is loaded (child pages), it is not an iframe. I currently use an Ajax request to obtain the content of the child pages in this way I can place the content of the child pages within the parent page. The problem is that the data only contains the body of the child page.

 $.ajax(
                {
                    url : URL,
                    success:function(data, textStatus, jqXHR)
                    {

                        $(target).html(data);
                    },
                    error: function(jqXHR, textStatus, errorThrown)                      
                    {
                    }
       });

I would like to know if it is possible to use the java-script or jquery to obtain the head of the html child, that is, only with the URL or, if not, to obtain the whole DOM?