Source: https://tomelliott.com/jquery/preventing-widows-websites-jquery

Remove widows in WordPress using jQuery

$('p').each(function(){
    var string = $(this).html();
    string = string.replace(/ ([^ ]*)$/,' $1');
    $(this).html(string);
});

// In Genesis, add this to the Header Scripts:

<script>

jQuery(document).ready(function($) {

  $('p').each(function(){
      var string = $(this).html();
      string = string.replace(/ ([^ ]*)$/,'&nbsp;$1');
      $(this).html(string);
  });

});

</script>